So far, I have been very blessed in the clients who have come my way; only one situation has not worked out. Sooner or later, another client is going to come to my door expecting concessions that I am not prepared to make: lower rates, an unrealistic schedule, changes in payment timing, and such.
Happily, I have avoided such problems up to now largely by taking the advice of those who have a lot more experience in these matters. For example, many have said not to agree to any terms without seeing the entire manuscript first. So, I have insisted on that.
What I failed to do in one instance, however, was to determine whether the manuscript given to me needed copyediting (my marketed skill) or something more advanced (developmental editing or line editing). That led to an embarrassing conversation in which I explained to the author that her work would require a higher total cost than I had initially estimated. She understood, and paid for the work.
Another piece of editorial wisdom that I have followed is to have a written contract that sets expectations for both parties and avoids surprises. Doing that has proven to be helpful by surfacing a desire by one prospective client to change the payment schedule in a significant way. That was a bridge too far for me, and we have not agreed to any work so far.
What got me thinking about all this is an outstanding article by an experienced editor (Ruth E. Thaler-Carter) about difficult clients, which is available here:
Before you run into a difficult client, be sure to take counsel from Ruth.