If you have not run into a plethora of horrible web design clients, consider yourself lucky. However, you should prepare yourself for the onslaught of horrible web design clients that you will inevitably receive.
No matter what they tell you, no web design client actually knows what it is that they want. If they did, they would design their own website. One of your main concerns will be navigating the politics of all the egos that you will run into.
You will have some web design clients that will get you descriptions that do not fit anything in particular. They will then expect you to take these generic descriptions and create something for them. You will have other web clients that will tell you exactly what they want, then proceed to reject every piece of web design that looks exactly like what they just described to you over the phone.