When friends give me free food or drinks, I usually tip the full cost of what I was given. So if you gave me an $8 drink, I would tip you $8.
This still benefits me in that I don’t have to pay that $8 plus another tip, but I’m wondering if there’s an expectation or standard that would save me some $
Sometimes this one place gives me $20 of food before closing when I only intended to spend $5 so the upsell kinda hurts
I don’t know what the culture is where you are, but I don’t give people money for friendly gifts. If anything, that just implies our relationship is transactional and shallow, rather than a community who care about each other more than money.
What I do is return the favor by giving them free things later, just like they did. Like buying them a drink at a pub.