I have found that if I "stew" over what fabric to use too long, it gets discouraging. What works for me is to spend a bit of time, maybe 20 minutes, making stacks of five fabrics that I like together. Then I come back later and look again and decide which stack I want to mess with. I also had to convince myself that if I "make the wrong choices," the world won't end. I go ahead and finish the quilt (because usually I decide that I don't like a quilt when I am in the middle of it) and I usually end up liking it.
I am very insecure about selecting fabric for a quilt. Often I opt for several shades of the same color, because I know those will go together. But I have finally, after four years, come to a place where I can just make a decision and go with it....not stew about it forever. Hope you get there too. It sure makes quilting more fun.
Dina