References are crucial. Anybody can advertise themselves as being good at what they do, and talk a good game when they first meet a potential Client.  But having references that demonstrate your skill and historical performance reinforces your capabilities and – more importantly in some circumstances – your ability to follow through with what you say.  Frequently, following through with your promises are even more important than your skills. In my own industry, one of the most outrageous things I hear from prospects is how they register their surprise that I have even called them back! Sometimes, it is the most simple things. Calling people back in a timely fashion is symbolic of your willingness and ability to complete the task for which you are being contracted.