tipping

I am a great tipper at bars and restaurants but I will be honest I am unsure what is appropriate tips for other things.

One weekend in college my roommate asked what I normally tip after getting my hair cut. Zero, I said. I didnt know it was expected. When I was really young my dad cut my hair. At three was I supposed to give him a frog or a stick as a way of saying good job (even though it wasnt)? Then I went to barber shops for a while and although I didnt watch dad pay, I am confident he didnt tip the barber. High School I would cut the yard around the salon I got my hair cut as part of a barter system. In college I began tipping after my roommate told me that was expected.

What about valets? How much should they be tipped? I am really asking what is appropriate. Should I wait until I get in the vehicle and see if they moved my seat or changed my radio before handing them a tip? Should the tip be equal to or a portion of what the paid lots are charging nearby?

What about pet groomers? We take our dogs every couple of months to get washed and have their nails trimmed. It is a lot easier to have someone else cut their nails then for us to do it. Our older dog has some hip issues and our younger dog despises having her nails done (she is this close to being sedated to have her nails done) plus I dont have to worry about cutting them incorrectly or too short. After our most recent trip to the groomers, we get home and find out that the older dog only had about a third of his nails cut even though we paid for them to all be cut. In the future should I look over the dogs and make a big scene if it isnt done correct before tipping?

I remember years ago I was making a cross country flight. A buddy of mine worked for the airline and had given me some free drink coupons. Somewhere high over the heartland of America I decided to tip the flight attendant as I thought she was doing a great job. She became offended that I had offered her a tip. I asked some flight attendant friends about it and most said they would have taken it but that some attendants feel that if they are offered a tip you are thinking of them as a waitress in the sky which they feel is below their stature.

Whatever. So who should you tip and at what amounts?