I hardly ever use a solid, the seem so flat. I do use mottled or fabrics that read like solids. I try to use a large print, medium, and a small print. It works out really well. It just takes practice, and if you still need help, I'll loan you my sister, she really has a way with colors.LOL I run everything through her. I also take my fabric I want to use into my lqs
and they help me fill it in, if I'm not sure. They are great.