For ultimate flexibility, Martins recommends twin beds
instead of a full, queen, or king. "Let's say I have two cousins coming," he says. "Having twin beds is so much easier. If there is a couple coming, you can put the beds together." Don't fear the gap between them—a specialty mattress pad can bridge it so smoothly that your guests will scarcely notice. Begin your best-bed search here: Find the Bed Style of Your Dreams.