After much soul-searching, I have decided to make all my consulting clients sign a formal contract before I do work with them. Upwork already provides a contract, but I found that their contract was not sufficient. People were taking advantage of me. So I have a new policy- you want to work with me, you sign a contract that you aren’t going to add  any more work under the same contract. So far, the two people I have given it to seem to like it. It gives them more protections, too. So, a win-win for everybody!