Spiros, years of making spirals has led me to use some very specific techniques for cutting and organizing the pieces of a spiral quilt. The PDF below (click on the title to open it) not only explains the process step-by-step, but explains why I do it this way. Believe me, whether you have 15 or 1500 pieces in a spiral quilt, these cutting and organizing techniques will make your project go smoothly.
Cutting (and Organizing) Fabric for Spirals
Happy quilting! R. 
