I think I am going with pearls but I have found a few that have crystals that I think are really pretty as well……
My dress is plain so I could really do either or….

http://www.etsy.com/view_listing.php?listing_id=29965439

http://www.etsy.com/view_listing.php?listing_id=28126543

http://www.etsy.com/view_listing.php?listing_id=27854817