Most effective: Large, flat areas significantly arms and legs.
Least effective: Curved areas cherish the underarms, and probably do cause significant trauma towards the face and other thin skinned areas. https://maps.google.com.lb/url?q=https://wikimapia.org/external_link?url=http://www.betsyrosspatterns.com/10-signs-youve-found-a-good-hair-salon-for-your-needs/