Here's a little chamois tip.

Wear the smallest size shorts you can squeeze your butt into! Really.

Too often I see women in the bike shop buying shorts that are a size or two too large because they're modest about wearing spandex. Well, when your shorts are too big, your chamois will move around (or bunch up). One of the best things you can do to improve your saddle comfort is wear tight shorts. Think of your shorts as a second skin.