Appropriate garden party attire is closely linked to location, so it's best to plan one with consideration to the other. Most guests love an occasion to break out the party garb, so don't hesitate to plan something dressy. But if you're serving burgers, guests may be more comfortable in shorts and tanks. If it's warm enough for a dip in the pool, be sure to tell guests to bring their suits. Theme parties are always fun, and togas perfectly complement a Mediterranean setting. Or, if you want to host a shindig circa Jackie O, make a wardrobe call for summer dresses and floppy hats. No Kennedys required.