In my experience, the worst customers are nitpickers - Clients with too much time on their hands who consider themselves experts in every aspect of design and marketing, and feel that they're obligated to find imperfections in anything and everything which is presented to them. I've found the best way to deal with this is to approach the project with a clear plan, and have the client sign off on each stage with the understanding that further adjustments will cost more.
Who are your least favourite customers, and how do you deal with them?
