Bandeau bras are getting pretty popular. I see lots of girls wearing them under see through blouses and lacey things. Another cute way to show them off is to wear it under a tee with big arm holes. You can make these from shirts you already have by cutting off the sleeves a little lower than where the bottom of your bra would be. You don’t want to show too much skin so be sure not to cut too low. I’d also advise cutting the neck slightly for more of a scoop. And be sure to bring a cover up (like a cardigan or something) so you’ll look appropriate no matter where you end up.