Be sure you like their work regardless of price. Paying a low price is still too high if you don't like the samples of their work. Also make sure you can get along with them through a bit of communication. If you are trusting someone with an important job, like your wedding, you want to get along with that person. Lastly make sure you get exactly what you pay for. A contract is as much for you as for the person you hire. Make sure it lists exactly the services they're providing, how long, and if there are items like prints, exactly how many and what sizes.