My rules for tipping work pretty well for me. It's just what I do, I guess others have their own system.For real. It's outta hand bro.
1) Never tip on top of taxes and other fees. Deduct those from the total before you calculate your tip.
2) Base is 15%. It goes up or down depending on quality of service.
3) Always tip cash. Never electronically, under any circumstances.
4) Never tip at the counter.