That's like which comes first the chicken or the egg..... I personally do both. And it is usually at the same time. If I find a pattern I love, I go get the fabric, but while buying the fabric for that quilt, I will find material I just have to have and will worry about a pattern later. I guess it all depends on who or what you are making the quilt for. How simple you want it, or how much work you want to put in it. There again I do both. Some times I just like to do something simple with pretty fabric, sometimes I want to do both hand and machine quilting, and need to take my time. So the answer has to be....do what ever turns you on!