Making blocks and making sure they've got enough contrast for my liking. I actually do this for any quilting project I do. It takes a a wee bit longer but it usually works out for the best. All of my QCA quilt blocks have been through this process.
Here's my next tip for this project: when buying fabric, it calls for 14 different fabrics per color, make sure you have a variety of contrast within the individual colors or you'll need to buy more fabric and you'll have quite a bit of repetition of fabric placement. This could be considered the down side of using what you have in your fabric stash but.. eh whatevs. Right? Until next time - happy quilting folks!