The Art of Making Leather Cases Vol.2 by Al Stohlman has instructions on how to do them (Handle # 17, page 21). I have made them several times (but I also have a rein rounder which makes it even easier). They aren't that difficult to do, and they are more comfortable on the shoulder and hands, if that purse gets filled and heavy). I am sure there are tutorials somewhere on this site, but I never did a search because I own the Stohlman books.
Oops, I think the handle you actually might want to use is # 18 or 19 on page 22.