Stever
You are really taking a big chance not using a contract.
In theory, yes, I know. But in practice it has never been an issue in 12 years. Almost all my clients are referrals and its not like anyone wants to play the "big jerk" when its possible it may go back down the pipe to the their friend, relative, co-worker that referred me in the first place. I also often develop personal relationships with my clients. I'm in their home every day for a week to a month and we chat about everything under the sun. And I always point out the little extras I do to ensure things are perfect (i'm a perfectionist) and they appreciate that I'm not just giving them an adequate average paint job. They realize I give a lot more than most to ensure top quality and are thoroughly impressed. Quality comes first, productivity is a distant 3rd or 4th.
And I also don't take a deposit up front, though on large jobs I sometimes ask for an advance about 1/2 or 3/4 into the job when I'm running low on funds to cover paint costs. Again never a problem.
Now, I'm not saying anyone else here on this forum should do the same. I may be a rare case, or just crazy

By all means, protect yourself with a contract. Tim's version looks like a good one to use if you don't have one.