Sending gifts?

You can send it to their email via Steam (don't have to be friends) or directly to them once they add you.

Just send the gift to his email address. You can see it on your GA's winner's page. Once he accepts your gift he'll be added to your friendslist automatically. He can't ignore you any longer :)

You can send it via email, but I would try to add them as a friend. Sending it through Steam is faster now because of the new trade restrictions.

you just can send it to E-Mail, maybe add "key" which says "send to e-mail" or smth. And no, you don't have to be friends, but it automaticaly adds you as friend when he accepts