ive been going to the same barber my whole life, never tipped the guy lol. i didnt even realize people did that till a couple years ago. but he works for himself, just rents a chair, so if he wanted more money out of me he could just charge more.
servers i think i tip well.
a mechanic or salesman, i dont tip but if they are very helpful or skilled i will make sure they know they have done a good job and i'll tell the manager how good the employee is. who knows, maybe it'll help them get a promotion or a better raise.