Good point but you don't know my hair dresser! After his previous "butchery", I am asking him, very politely ofcourse..I think the من فضلك makes it obvious that you're asking someone to cut it for you.
Thank you Cherine. I know language is not mathematics for I have studied both. But if ever there was a language close to mathematics, it would indeed be Arabic!Qureshpor,
Language is not mathematics, there can be many ways to convey the same idea. The important thing is to convey it.
As I said, if you want to do something yourself, there's no need to say من فضلك . But in your scenario, you can say -as Iskandarany suggested- بنفسي which would clear any misunderstanding.