Think hair bands are only for long pony tails? Not so. The tiny ones, which you can find in any hair-accessory aisle, can make a short do so much more interesting with a few carefully placed spikes or a couple of low, choppy pigtails just behind the ears.
Choose clear or neutral-colored bands to minimize the school-girl look (unless that's your thing). It's a more grown-up style when they blend in.