Generally speaking, there are 4 types of clients:
1) Very knowledgeable and know exactly what they want.
2) Very knowledgeable, but don't quite know what they want (happy to delegate).
3) Not knowledgeable, but know exactly what they want.
4) Not knowledgeable, and don't quite know what they want.
#1 and #2 are good to work with, although I'm partial to working with type #2. Type #4 can be okay to work with, sometimes, but #3 you need to stay as far away from as possible no matter what they try to lure you with. They do not delegate any of the decision-making and will insist on things you know are terrible.