I am such a big fan this whimsical and romantic hair trend:
When choosing a fun headband for your wedding, a few things to consider:
1) Overall Wedding Style
You want your headband to "shine", but you also need it to coordinate with your style of wedding. Going Vintage? Find one with a fun brooch with stones and fun vintage details. Whimsical wedding? Find a headband with flowers and leaves.
There are so many options out there it would be easy to match your overall theme!
2) The style of your gown
Following the same idea as above, you want your bridal headband to coordinate with your dress as well as overall style. If you have lace in your dress, find one with a similar fun lace style. Have a lot of bling in your dress? Find a fun simple headband with a few rhinestones. Keep the theme going. If your dress is "loud" and busy, find a simple single band headband without too much detail.
3) Hairstyle to wear with headband
Bridal headbands are very versatile and can look good on up-dos or with hair loose, again mostly this may depend on the styling of your wedding dress as a dress with lots of detail may benefit from hair being worn up (or cut in a shorter style). If you are more of a boho bride try something beaded with lace such which could also be worn lower, across the forehead.
Stay beautiful my friends:)