Once upon a time the bridal headband had (read: had) to be attached to a gathered pouf veil.  Thank God these days you can wear a headband with or without veiling.  For me, headbanded brides have that fresh, Ralph Lauren/Eastern Seaboard look perfect when paired up with classic bridal gowns.  Bands range in style from simple, narrow satin ones to those covered in pearls and crystals.  Bands are a great option for hair worn down, not quite shoulder length like a bob.  Here are a few from my own collection pieces worn with and without the veil. 
Top Photo: The Oralie Headband by Amy-Jo Tatum//Photo by Shannon Stellmacher Photography
Photo 2: The Oralie Headband and Cathedral Veil by Amy-Jo Tatum//Photo by Larry Placido Photography
Photo 3: The Nefratiti Headband by Amy-Jo Tatum//Photo by Sweet Light Studios