Great page (in Japanese) on how to wear kanzashi. Yes, there are rules.
日本髪::::how to adorn traditional Japanese hair part2 The Kanoko : bending and tying in , you can decorate the back shot . 5. Before comb - flat casting set : I am plugged into the roots of bangs and topknot . 6. Ball hairpin : You inserted horizontally to flat out hairpin and symmetry .
1. Tabi 2. Koshihimo 3. Erishin - collar stiffener, put in the han eri (nagajuban collar) to better keep its shape.4. Datejime 5. Kohlin belts - hold the nagajuban and kimono collars at the proper angle. 6. Obi ita 7. Obi makura 8. Another obi makura, this one is for fancy obi musubi such as tateya and fukura suzume, but can also be used to tie an otaiko 9. Minibelt - apparently this felt-covered strip of rubber is used to temporarily hold the folds in obi musubi 10. Sanjyuu obi himo
Fantastic Nihongami blog where the girl does a lot of cool styles.