Yes, you need to tip your barber, gentleman! Tipping your barber typically should be around 20%, just like going to a restaurant and receiving excellent service. If you appreciate the service and think they do a great job 20% is more than fair, and if you think it is an amazing job you can even go 25-30% if you’re up for it. Sometimes it just comes to a rounding game though, too. For example, if your haircut is $30 you might give $40 and call it a day and the barber will be super appreciative of the few extra bucks.
It is really at your discretion and there is technically no right or wrong answer, but if you are going to see a person/barber pretty regularly you should tip them nicely as it is a relationship you want to develop and have a good rapport with. No one wants a bad hair day (or month). Also, if you’re a good tipper and are in a time crunch, barbers will bend of over backwards to help you out and get you in for a quick visit. Help me, help you!