Once you're suited up in a period costume, be prepared for a Halloween celebration of epic proportions!
You can do it by staking claim to a premade Caesar, Spartacus or Mark Antony costume -- you'll find plenty of variations at online and traditional costume stores.
An easy, inexpensive alternative is to pull together your own ancient look. Simply don a long or short white tunic or wrap yourself in a white bed sheet to create a do-it-yourself toga. For accessories, think a gold chain belt, lace-up sandals, a length of fabric draped over your shoulder, or a warrior's helmet.