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 just tip the amount I would have tipped if it was something paid. In practice that only happens to me in bars if the bartender gives me a drink on the house and I’ll always tip in those situations. Always tip your bartender :)