Guess I'm the exception. I've never made a client sign a contract. After 22 years of design work I've gotten burned probably a total of 6 or 7 times. I generally do between 20 and 45 projects a month, most of them logos and illustrations, all on trust. Having someone sign a contract is almost like saying "I'll do the work, and whether you like it or not, you're going to pay me." I stand behind my work and clients have no problem paying me when it's done.