Humble Monthly

It doesn't really matter. If you cancel early, you don't see or receive next month's games, if you cancel late, you'll get next month's games anyway. Otherwise it'd be abusable. So it depends only on how long you want the subscription for. If you only want it for June, you can cancel anytime between receiving the games and until the July bundle is revealed.

I usually do this, you get the monthly and the secret games, but you lose the store voucher (10% in humble store I believe)

EDIT: It's a good thing to cancel it later if you intend to buy something off of the Humble store.

Pretty helpful responses, really.

Yeah, I'm off of it by June 3rd once the games are revealed. Glad to have Rocket League at least, it's about the only game that has ensnared me to get it.

Not sure about the 10% off but you can unsubscribe as soon as you get the Rocket League and you will still get the other games in June.