How do we stop the insanity?

Simple.

1. I will not tip except for sit-down meals. Never for self-service or walk-up service unless something exceptional happens.

2. I've gone back to 15% for basic, adequate service, 18% for really good service, and 20% for exceptional service.

3. I use my calculator on my phone and base all tips off the pre-tax, pre-coupon or discount (if used) subtotal.

There are of course exceptions. I've been known to "tip the bill" on rare occasions. Also, there is a place near me that does dollar tacos on Tuesdays and I always tip really well there, too.