If you have an old black bra strap (or even one from removable bra) you can easily fasten it around your head and pin on an embellished bridal applique (you can get this at most sewing stores...mine was a small length of rhinestone-beaded bridal trim - about 4" simply snipped off the roll, for $3.50.)
For more staying power, hand-sew the piece onto your bra-strap.
(Or you can sew it onto a plain black stretchy headband from the drugsture.)
You can also snip apart an old bra-strap and handsew the ends around a small hair elastic - just tight enough to hold the strap around your head.
Pin on a pretty brooch you want to showcase. Voila! Instant glam - for mere pennies!