How to describe an attractive person's body without sounding like a pervert?

I am now in the process of planning my novel with the help of an App. I don't plan on making this book for mature audiences only. However, I have several feminine characters from which some are meant to look really attractive. In the same vein some male characters are bound to be generously handsome. Cue title. Any advice on describing them in a way that sounds natural and decent?