It doesn't matter if we're talking about boys or girls - when it comes to elegant hairstyles for children, there is a fine line to manage. You want his or her hairstyle to look formal but feel more casual. The reason is that most kids do not want to be bothered with looking formal because there is a perception that doing so will take more time and effort than most kids want to think about.
Of course, much of this perception is gender-specific. For example, when you want to style a small girl's hair, she won't mind you brushing and re-arranging it - it's like she is having her own makeover! However, when you are styling or cutting a boy's crop, be aware that the longer they sit in the chair the more frustrated they will get. This is why, for boys in particular, it can be useful to take them to a professional stylist instead of trying to do it yourself.
