Definitely scour the thrift stores (and closets

) for suits and gowns. Dead flower corsages would be a must (and don't forget for the guys). For a contest the 70's theme would be good, but may be limiting in trying to clothe the participants, it would probably be lost on the ToT's as well.
But you never know.
I think just the Dead Prom theme would be good enough, then it would be easier to get the costumes.
Now the theme for your floor is a Dead Prom BUT what is the theme of your prom?
That will help you focus on needed decor. Is this undead throwing themselves a prom? Or a prom where nobody knows they are dead ala zombies. That will help you direct your search, too.
One of our proms was Stairway To Heaven, so we hung stars all over from the drop ceiling. Another was Castles In The Sand, so we had piles of sand with glitter mixed in with little sand castles and stuff and the backdrop for the picture area was a giant beautiful sand castle picture.
So don't forget to incorporate the ceiling and a snack table, your refreshment table with the "spiked" punch bowl is a great start.
Oh, and the wallflowers! Guys on one side and girls on the other of the shy prom-ers.
