When we are consider our fabric, we look for "star power" and we look for "background singers". In other words, we need a dominate fabric (or fabrics) which engages us. Then we need more subtle fabrics to compliment this dominant fabric.
But one thing, we've failed to mention is the value of these fabrics. Very often, our dominate fabric is a medium value and we may have chosen more medium values as our complimentary fabrics. We also need to chose fabrics, not looking at the color but at the value.
If you have trouble determining the value of a fabric, look at it through a value finder (red glass or plastic), through a camera lens or from a distance of 6 feet or more. What happens is that the color is obscured and you will be viewing the value of the fabric. Really stumped, a black and white copy of the fabric will completely eliminate the color, leaving only the value.
Why is value so important? This is what adds definition to our shapes, and added interest to our project. It is what creates a picture out of color moosh.
I fine-tuned my project colors by adding more contrasting values and started making log cabin style blocks.