I cut my DD's hair because it is really time consuming to cut her hair and needs a lot of sneaking to cut a babies hair. And it also happened twice that my cut had needed my MIL's hand (she's a hairdresser)..lol. My baby is a girl but if its a boy frequent visit with a barber shop will surely be in my schedule.
A friend who is a hairdresser (and grandmother of four) follows DD round the room whilst she plays, snipping off wisps .
When she needs a proper trim she sits on my knee in front of the mirror and the same friend snips away as DD whips her head around trying to look at where the snipping noise is coming from.
You need to see a hairdresser who is used to children - most salons have at least one. A salon near us even has two car shaped children's seats (actual car shapes, with steering wheels, chassis and wheels etc that they sit in - like a shopping centre ride) to cut children's hair in.
My DS is 11 months and had his first haircut just before Xmas. I just took him with me when i got mine done (rang and asked first)
He sat and watched me get mine cut then i stood him on my knee so he could see himself in the mirror and my hairdresser snipped away. It's not perfect but looks much smarter (he was getting to Oasis band member stage!)