tell the hairdresser you want a haircut which is "indescribable" and he/she will give you the "try hard azn, biggest fag" haircut ever.
Or as previously stated, take the photo in. OP, i must say, what a stupid question, obviously the only way to let the hairdresser know what cut/style you want is to show them a picture.
How do you think Becks does it? He has comics of Mr T, and get his cuts from him.