Contracts are fantastic. After 2-3 years of not asking for one, I finally bit the bullet and put one up on my website:
Booking | Carrara Nour
Mine is a hybrid of a few contracts I've seen before, plus a couple tidbits of my own. Yes, sometimes, it makes me feel like a hard-a**, but it's better to be proactive than to put up with last-minute cancellations and other B.S. if there's a way to help protect yourself against it!