What are the guidelines for tipping hairdressers?

The tipping in my opinion has gotten out of hand. Not everyone can afford a 20 % tip. To me a tip, even if it is small says thank you. Here in the States it has really gone overboard, it seems that these days almost everyone in a service oriented environment expects a tip and some of them make a pretty good hourly wage (and I don't mean waitresses, who really need the tips). I try to tip well in restaurants, but anywhere else I usally let them know that I can't afford huge tips, because I don't make much money myself. People usually understand and appreciate that. I don't know if I could help, but this is how I deal with it.What are the guidelines for tipping hairdressers?
uhh????What are the guidelines for tipping hairdressers?
20% of the price of service is customary- unless you are not satisfied, but in that case you should bring it up, either to the stylist or the manager/owner- so they can remedy the problem.