Well, just as its important to be able to draw someone from the front, you may also wish to draw them from behind. In which case, it helps to know how to actually draw someone's behind. ^_^ I wasn't going to add this, but since many anime girls are draw in skin tight suits or swimsuits, it's kind of important. Umm... I don't know quite what to say; just be careful how you make the legs connect to the rest of the body. There's more info in the next section of this tutorial. If you need extra reference, get that figure drawing book by Burne Hogarth mentioned in my recommended reading section. He has several pages devoted to the subject. -_^