You are expected to tip in restaurants and bars. It's built into the pay scale. A restaurant actually can pay their staff a base less than minimum wage in anticipation of your tips.

I use 15% as my standard on restaurant tipping and move up or down based upon service. Usually I do give 20% as Tony suggests since most of the service I get is very very good - especially if they let me have a pitcher of ice water - I'm big on ice water with my meal. If I don't get a pitcher, they better be good at filling my ice water.

My tipping on bar drinks or items at sporting events is more based on the number of drinks than the price. If I'm with a group and want the barperson's attention, I will tip big the first time to get better service for the night. But, usually I only have 1 or 2 drinks so I really don't tip well in bars.

I tip service people OK. I haven't stayed in a hotel in years but I used to leave the girl money for cleaning the room if I was there for more than 1 night.

I tip the baggage guys at the airport when I give in my bag(s).

I tip if someone loads things in my car [like securing something large] or delivery people of large items to my apartment if it is done well and on time.

I tip moving men [though that hasn't come up in a couple of decades].

I NEVER tip at fast food. It always pisses me off to see a tip jar.

In the Hispanic neighborhood adjacent to mine they have small non-chain supermarkets. Often they have people, young kids and older women, who pack your bags who have tip jars. I don't think these people are considered employees. I don't know why they are there exactly. If I pay in cash, I tip some/all of the change. If I pay by CC, don't tip.

My tipping for take-out delivery - like pizza, chinese, fried chicken - is below par and doesn't change based on the price/quantity. I don't have take-out much anymore, but I used to give chinese food delivery people less than pizza. My tipping improved if I became friendly with a good delivery person. If delivery sucked, I would just call a different restaurant the next time.

For baseball games, I would try to avoid the guy who wipes down your seat and wants some cash. I hate those guys. But, I used to tip ushers I knew at Shea in the 90s if I wanted to improve my seat. I used to buy an upper deck ticket and get a great box seat. Otherwise, unless I can't find my seat, LEAVE ME ALONE!

I tip taxi guys well [20-25%] if they are efficient, friendly, don't play the radio and provide a clear receipt. I hate if they insist on a route different than my suggestion especially if it doesn't work out. When I would be stuck in the city late, late night [say 3am], I usually negotiate a decent price to get a cab to take me to NJ. The tip would be in the price.

My mom, who has Lupus, tips the wheelchair personnel who take her around at the airport. I noticed that they wouldn't take the money in Germany and Austria.

And, though I haven't been in quite some time, I used to tip strippers.