1. Listen to the band - Step one before you do anything else, should be listening to the band. You can do this very easily by visiting the band's website. Take a listen, and preferably a look at some of their live performances, and see if you think they are a good fit.
2. Read the reviews - What do there customers have to say? It's best to find reviews that are not on the bands website and this will give you a more realistic overview of feedback.
3. Go through their set list - Do they play the type of music you are looking for? This is a crucial question as the vast majority of the time, there will not be enough time for the band to learn an entirely new set list for the day.
4. Go to a showcase - If they passed the previous tests, then its time to go see the band live!
5. Discuss your requirments - Can the band provide you with what you require? Are they available? If so, then go ahead and book the band!