Most effective: Large, flat areas like the arms and legs. Least effective: Curved areas which includes underarms, as well as cause significant trauma on the face together with other thin skinned areas. If you cut mens' hair then you will need hair clippers too. https://www.google.at/url?q=http://www.suubinc.com/7-essential-tools-every-aspiring-hairdresser-should-own/