When a strapless bra won't do, go for a pair of clear straps. These are dirt cheap at Target and a great addition to any girls lingerie drawer.

Most bra strap showing is tacky so these lovely little straps hold your bits up without calling undue attention to what you happen to be wearing underneath it all. I have also found that the plastic adheres lightly to the skin which eliminates infuriating strap slippage. This is a great brand too because each pack comes with 3 pair so it's a good bargain.