Despite how you may feel about tipping, it is customary in the U.S. to tip 17-20% on the cost of services received. The percentage is the same for servers as well as hair stylists and anyone in a "tipping" industry.
Budget a tip into the cost of your activity. If you are going out to a restaurant and can afford the meal, but not the appropriate 17-20% gratuity, go somewhere you can afford. If you are going to a salon make sure you know the cost of the services you are receiving so that you come prepared to tip appropriately.
Step2
Think beyond the dollar amount of the tip. People that support their families with the income of a tipping industry take the gratuity you leave personally. It is the monetary value of what you thought of their product, effort, and personality.
Step3
If there is a problem with the product and/or service, and you don't feel the experience you had is worth a 17-20% gratuity; let a manager know. When your at a restaurant and your food comes to you cold, prepared incorrectly, or in any way not what you wanted, let your server know. If you are unhappy with the service or attitude of your server, ask to speak to a manager.
Step4
When you receive a salon service that is below your expectations, always politely let the professional or the front desk know. They will usually allow you to have the service redone at no cost.
Tips & Warnings
You don't know how to calculate percentages? Most cell phones are made with tip calculators these days, or at least a regular calculator. The easiest way to calculate a tip in your head is to just leave 20%, so a $100 tab would be $20
Always always always tip on the ORIGINAL bill total. If you have coupons, discounts, or specials of any kind, even happy hour; tip on what the bill would have been without those extra discounts!!!
Remember an extra $2 may not seem like that much to you, but it is the livelihood of your server.