Shopping on Etsy.com, I found a woman who makes GREAT snap-on bows!! They tuck the hair into an elastic band, but snap closed. Hard to explain, but I just got Sophie's bow (in pink leopard w/ a fancy little sparkly touch on top) and I am loving it! The bow is beautiful and really well made, but beyond that, IT STAYS IN HER HAIR!! She has really fine hair, so I was thrilled to find something that works for her. (Barrettes just fall out, and I feel like the rubber bands pull too much on her hair.) Here's a link to the site:
View Single Bows by snapinbows on Etsy