Last year I bought a brown fabric wristlet from Payless Shoes for $15 to use it as a small purse that could carry all the essentials (money, ID, phone, keys, lip gloss) when I wore a skirt or a dress for a night of clubbing. I've used it so much since then that the wristlet has turned out to be a smart yet inexpensive investment. It's neutral and versatile enough to go with anything, and its look echoes the sleekness of more expensive Coach versions. Plus the size is perfect: it's just big enough for the stuff I need to bring with me and nothing else, so I don't feel burdened like I would with a larger handbag. When I want to do some serious dancing or I have a drink in hand, I let the purse dangle off my arm so I have both hands free. I've been a big fan of these fun little bags ever since.
If you're looking for a signature piece, feel free to buy one in a fun colour. However, if you want a luxe-looking wristlet you'll use with many different outfits, go for one with neutral colours and details like metal hardware (buckles, zippers, studs, grommets), leather trim, signature fabrics, and mini pockets. Getting the look of a luxe wristlet doesn't mean you have to spend a lot, though; often a popular style from a high-end brand might be knocked off by such brands as Nine West, Aldo, or Payless.
Regardless of the price range you have in mind, choosing one that's the right size and shape is key. You want one that's just big enough to carry your stuff in but not so big that it feels uncomfortable. The other downside of a bigger wristlet is that it might hang awkwardly on your wrist and possibly clobber your date when you move your arm (not good!). When shopping, try putting your cell phone in the wristlet; as a girl it's often the biggest item you'll probably carry to a club and unless it's a Razr or some other extremely thin phone, you'll need to experiment just to make sure.