How do you decide on a Smartphone ?

I have my feature requirements
sim+SD(nice to be able to hotswap from your music, to different music, videos, etc by swapping SD card(also good for a local secondary backup for pictures(cloud storage requires data connection which you might not have... also limited data plan here($15/mo for more than plenty of data(have never hit my limit... and that limit keeps increasing) and unlimited everything else), headphone jack(non negotiable to me... I like my cables thank you), good battery life, not a crap cpu, fully functional on GSMT... and USB-C(this is pretty much standard now so).

then preferred features... IPS LCD(I don't care for an OLED so I don't want to pay for a display that is more fragile than a cheaper tech), higher internal storage(so I don't have to worry on vacations between pictures/videos/etc...), I would like another flip camera or something with a very high quality front camera... as when I do take pictures its usually vacations/important events so I want high quality photos.
and hope for a midrange pricing

still using my Asus Zenfone 6 from launch(this phone checked almost all the boxes for me... its extremely rare that I get excited for a phone release and it got me to preorder it)

If you want a longer support cycle, you might want to check if your device is supported by an open Android port, like LineageOS.

I usually buy in the budget to midrange and try to use it as long as possible. Last one for 4 years, recent one for 3 years now.

Edit: was not finished, but got distracted...
How do I decide?
No vendor lock, dual sim, better than my last phone.

i hardly replace my phone. i only bought one phone ever since i started working, which is because my old phone's screen was cracked and won't turn on anymore (replacing the screen cost way more than the phone itself). but since i know that i hardly replace my phone, i always try to buy the one with a better spec so by the time i will have to replace it, it won't be super outdated.

if there is a phone with replaceable battery by the time i want to replace my phone, i will probably buy that one so it can last longer.

I currently am using my 7 year old Samsung s8+.
It is time for an upgrade but here is the thing.
New flagship phones are expensive and the other phones in the big companies line up dont seem like that much of an upgrade
( mind you I dont use my phone for gaming)
And I feel that the new midrange phone dont offer that much of an upgrade.

Maybe if the S25 next year brings innovation, I might go for that one.
Or likely keep using my S8+ until it gives up on me.

I use my phone till it's dead and I also buy phones if they're unlockable and ROMable.

1. Start with anything already on the market for at least one year, so you can find honest reviews.
2. Check your budget

It'd be nice to be able to drop $1k on a phone every few years, but that's not always possible. So i also often look for refurbished or used phones no more than a year old, as they're usually in very good condition, and get you a huge price break.

Generally i'm looking for an android phone, with more capability than my last. Such as larger storage, so an option to expand with an sd-card of some kind is preferable.

I usually spend 300-400€ for some midrange phone. Stuff like headphone jacks are irrelevant to me, features like NFC are my priorities. But I guess that's the standard meanwhile.
Otherwise I don't have specific demands, such as "best camera" or huge battery. A phone shouldn't have any greater weaknesses though. At least three years of Android updates are a must.

As my current Samsung Galaxy A53 is two years old, I might get tempted to get something new by the end of 2026.

I don't use them. I prefer phones with buttons. That said, you occasionally run into something that insists on using an app, so I do have one. I got it free from my telco. Nothing special, Samsung 5G. If it breaks, or becomes obsolete, I'd get another free one.

For me, it is opposite to choosing pc. When I buy pc I analyse and choose every part. With phone I just choose samsung flagship but I usually take not most recent but previous generation because of promotions and orices. I only check briefly review to confirm it does not have unexpected flaws. I also change them very rarely as I don't 5hing point to change it recently. Not long ago I changed s8 into s23.

I bought my first smartphone (Doogee Smini) this year. I chose it because it had the closest dimensions to my dumbphone (Sonim XP2.1), so I knew it would fit in the phone pocket in my bag.

I look for a good Redmi online to spend 100-200 euro and have a good phone for next 5+ years.

i only buy a new phone or get it gifted to me after the current one either dies or doesnt get support anymore... happened to my huawei p20 lite.
since i know i will use it till the end its ok for me to invest a bit more money into it. got a samsung galaxy s24 gifted to me... honestly no clue what it cost XD

my current problem is that phones are getting bigger and bigger and wont fit into my pockets anymore ... also the reach with my thumbs just goes so far. so the only reason why i got a galaxy s24. because its about the same size. of course its faster but the fact that the notification wont group themselves if under 4 or 5 notifications annoys me a lot.

Still using Galaxy S4 from 2013. Dropped in water many times, including salt water. Still good, but have to use ear buds because the media speaker connection has died and the plastic/metalic casing is falling apart by this point. Rocking the poverty look ;)

I did get a ROG phone 6 this year. Simply, because apps no longer want to work on my 'outdated' one. Including 'play store'.
Use it for entertainment purposes but prefer the S4 - it even boots faster than the ROG6. I'd wager, something to do with in-built google bloat/spyware I can't remove.

Find the narrowest phone I can with decent specs. Seems like still Sony Xperia 10 series...

My mindset is to get a phone that will last as long as possible without having to buy another one. So a lot of RAM, large battery (replaceable would be cool but that's very rarely an option), lot of storage or expandable storage. Specs don't matter as much because I don't game or use heavy apps, screen size and thickness is whatever too, I like using wallet cases so it's going to be a brick regardless. Personally I also avoid Chinese phones, I give China enough of my money.

I had a Motorola G3 from 2015, with 512MB of RAM, until 2023. It was usable for texting and calling, but trying to watch Youtube or use basically any modern app for ordering food, banking, etc. was impossible.

In 2023 I bought a refurbished Samsung S21 Ultra with 12GB RAM and 256GB storage. It was two years old at that point, but 1/3 of the retail price for what was looked like a brand new phone. It was significantly better than any new phone at that price, including Xiomi phones that often have good specs for a low price. I would definitely recommend this path if you want a good phone for cheap, as long as it's refurbished properly (ie. in excellent condition, as new).

I like phones that are good value and have been using Google phones for my past 3 phones, Pixel 2XL -> Pixel 4A -> Pixel 6A. I typically buy 2nd hand so it usually lasts about 2-3 years before I get a new one. I got my 6A at around 300USD 2 years ago and it has been serving me decently enough.

Unfortunately, I think I'm quite done with Google for now and have been quite interested in the Samsung Fold so maybe I'll get it once my Pixel dies. I just find it so cool and I rarely find phones cool.
I still find it quite intriguing that there are 'locked' phones in other countries because such a thing doesn't exist where I live.

Almost always 2nd hand, but a year ago I did buy a new Samsung M23 5G.

I usually look for a few features, that I need/want (this time it was mostly 5G, that's why i went for a new one, 2nd hand offer was very limited), and then for one of the cheapest options.

I don't care about visuals, about quality of screen (as long as it's a pretty large one) and other stuff, that tries to make a mini laptop/tablet out of a phone, Previously I did care about quality of camera, but currently practically all of newish models offer cameras that are sufficient for my needs. I do however look for products, that are expected to work for quite a long time - on average I use a phone for well over 5 years. Actually my last phone was LG G4 (model from 2015, bough 2nd hand and chosen then for its camera), which I probably would still not replace, if I realized, that its weird behavior has been caused not by it's defect, but by faulty SIM card. Still, 5G is already useful for me, so that's OK.

There are also countries, which products I try to avoid, even if I'm to pay 5-10% more... but not, if I'm to pay 50% more ;).

My current rule of thumb is a mid-range brand phone for ~$500. From my experience those are suitable for most tasks I need.

200-300, not something too cheap and not something too expensive, it's a phone not a computer.

And battery power.

My phone history: Nokia 1680 Classic for 6 years, Asus Zenfone 2 Laser for 2 years, Nokia 5 for 4 years, and now Samsung Galaxy A12 for 3 years already. All my previous phones were passed down to my family member.

I'll use my phone until it breaks, or it can no longer cope with my gaming demand. The budget for a new phone is no more than 200$.
For my next phone, I'll choose the one with the best performance and the smallest size within my budget. I carry the phone inside my pants pocket, so a large phone is hard to fit.
My current phone doesn't have a compass nor NFC, which is inconvenient sometime.

I prefer the OEM experience, so no third party launcher. Maybe one day I'll install a custom ROM, unlikely.

I stay away from Chinese brands because I consider China's foreign policy as hostile.
Say no to local brands like Vsmart or Bphone. The former is outsourced to China, while the latter is overpriced.
No Apple. For that amount of money, I would buy a laptop, and maybe a phone.
If two phones have the same specs, I'll select the brand that I've used in the past.

It's incredibly simple when I'm limited by budget=I get the most power for my buck.

So that means my second phone in a row ended up being Xiaomi lately. It feels like night and day after my Samsung run where these specs would cost me twice or thrice as much. I'd like to have a better have camera sure,but for a budget option I just want as big of a battery as possible and a phone that doesn't buckle under stressful usage if need be(I don't do gaming on a phone,but I'd like to see zero lag if I'm doing 30 tasks at once).

Sadly the trends set by cancer like Apple trickle down to seemingly every brand and now you are buying a phone in 2024 and don't even get headphone jack or sd expansion card slot. The only real innovation in years in this space seems to be a foldable smartphone which looks cute and might feel nice not to carry a brick in your pocket. Everything else is just reiterating same shit(more thin phone! better camera! moar power!)

Whenever I get unhappy with my current phone, I quickly check what the market looks like. To save time, I first check the latest series from my current brand and compare to my current phone. If the difference doesn't seem that big, I reconsider if I really need an upgrade or should wait 6 months more.
If the difference seems worth it, then I dig a bit more, still within the latest series of my current brand, to pick one or a few best matches based on specs. Then I look for reviews and comparisons with other brands. I also look, if possible, at information about the upcoming series (expected release date, expected new features), so as to avoid buying something like 1 month before a new product with an important new feature or upgrade gets released. Although it may sound like I'm attached to a particular brand with what I described, I'm not. That's purely to be more efficient when doing my initial research, but when comes the moment to actually pick I look into all options.

When all this is done, I generally have a good idea of what to pick.
As I don't do that much on my phone, I'm usually in the lower-mid segment I'd say, by choice. Less than 180€ as far as I remember, but I snatched quite a good deal. For my next one I'll probably aim a tiny bit higher, as the "disk" speed seems to be an annoying bottleneck on my current phone, compared to barely more expensive phones that other family members got. Still I've had my phone for about 3 and a half years I think. I'm still using my previous phones as backups / throwaways for suspect apps / rooting experiments, up to my old OnePlus X from 2015, and I expect to keep the current one as main for probably a year and a half.

I'll use my phone until it breaks or barely functions, I will then set a budget and aim for the best value for that budget, usually £300-400. Android is always more capable than iPhone. Only reason I got rid of my previous phone is cus I dropped it a few too many times and despite the protectors it went a bit woohoo, lol.

Currently my approach to phones is fairly simple: I mainly need it to run WhatsApp, Firefox, and YouTube, if it still runs those three apps well enough then everything is fine, if it starts struggling then I consider changing it, if I've been thinking about changing it for roughly a year then I'll go ahead and get a new one. I got my first smartphone as a hand me down around 2014 and so far I'm on my fourth one, I'd likely still be on my third one if that one hadn't broken. But I don't aim for anything too expensive, currently using a Samsung A12 and I'm happy with it, plan to use it for as long as possible.

Back in the 2000's however I was genuinely interested in phones and was loyal to Sony Ericsson, at the time phones were gadgets and objects of desire to me, every single one that came out had significantly different features and there were a wild array of distinct of shapes and designs so keeping up with the new releases was fun. I really miss those days. Then smartphones and touch screens became the new trend and by comparison they were aggressively boring to me, so I stopped giving a fuck after a while. Nowadays I approach phones the way I approach computer hardware, a means to an end, a tool where the only important thing is getting a good bang for your buck.

I tend to look for a phone which has reasonable prospects for still being usable after 3-4 years, so I personally put the budget phones to one side and focus on the mid range (flagships will probably be forever out of my price range, even after a year in this country they're still quite pricey). Used a Nexus for a few years until it died for good. Tried a "mid-range" Samsung at what was probably the worst of the Tizen era, totally put me off Samsung, although it isn't really an issue these days.

Right now I'm using a Pixel 4a5G bought at the end of 2020 and I'm happy, for what I do with it (almost everything at the moment) it still feels the same as when I bought it (though it will be time soon to consider LineageOS). I tend to like the Pixel philosophy as it were, it "just works" (when Google fixes their bugs...), the camera is great for point and shoot and the bloat is minimal & let's me customise as I like, mostly. That said for longevity I have one of the last Pixels with a Snapdragon Soc so I can't speak to the Tensor performance of recent pixels. I do know now you tend to have to accept what you could call philosophical compromises to use pixels, trading software & camera bells and whistles for performance compared to other flagships.

If there's two things about phones I swear by it's doing a decent amount of research and never, ever buying phones at full price, most of the time they aren't worth it and Android phones especially get discounted fairly quickly. I got my 4a5G $150AUD off just a couple of months after it came out. Wouldn't have considered the original price.