Anyone who has designed websites for any length of time knows about the potential hazards of web design clients. While some clients are great, some web design clients simply do not know what they want, and even when you design the website to their specifications, may ask you to change it several times. This becomes old and tiring, especially when you know that you may well have to change things as the client demands.
Watch for clients who sound like they do not know what they want or want you to come up with the entire design yourself. These are the hardest clients to please, and the ones you will have the hardest time collecting payments from.
It is easy to protect yourself when you follow the right steps. Make sure that you get at least half of your money upfront, and that you have the client sign a contract. Without a contract, you will be at risk of making more and more changes, which will slow you down on other projects.
From: Web Design Schools