1. Try some mix & match stuff.
For instance, I have a pair of black pants with this "slinky" fabric that doesn't wrinkle. I'll usually wear them to dinner @ least twice, with different tops. Who would know? I usually change after dinner anyway, to something more comfortable.
2. Shoes. Shoes. SHOES! They take up so much room, and I usually don't end up weraing them all, anyway. Flip flops, sneakers/ walking shoes, and a pair of nice dress shoes that will go with anything, and you're set!
3. Make sure you have a clean set of undies and a bathing suit in your carry-on luggage.
(And another set of street clothes, if you have room)If they lose the rest, you will still be able to have fun and "make do".
Mostly, don't sweat it! It's vacation, and (for the most part) people will not care what you're wearing. They'll be too busy having a great time!