Your daughter is now embarking on the road to growing up into a woman. Let the 16th birthday be an opportunity for her to get introduced to make-up and things needed for her to look great! For that, a fantastic theme would be to invite the guests to a local spa (or take them there from your place) or if possible, have a spa area set up at your home. Make it like a real spa (if at home), complete with massage, pedicure, manicure, and make-up application. As party favors, gift the guests with something like a lip-gloss, a nail polish, or a nail file!