From the "Clientsfromhell" website...
The best way to avoid a lot of complaints that come with freelancing is to screen clients. However, not every client from hell has a pair of horns sticking out of their forehead. Here are some signs that you may be making a deal with the devil:
Ambiguous expectations: A client is employing you because they lack the skillset or resources to complete a project themselves. However, the client should have a clear idea of what they're after. Failing that, they should be eager to help you help them figure it out. Clients who fail this test have project scopes balloon overnight, or they react with anger and confusion when their idea of what they wanted doesn't match the freelancer's blind attempts to give it to them.
Unappreciative: A client's expectations may not be explicitly tied to the project itself; they may expect behaviour, time, or discounts for no other reason other than they think they deserve it. Unfortunately,