Your strips will all be cut different lengths so you can choose your favorite fabric for the largest strip if you like.
While you will have different patterns on your fabric strips, Bonnie and Cindy suggest using the same solid fabric for your sashing strips. You can change it up but keeping them all the same will bring some consistency to your quilt in the midst of all the different fabrics.
Bonnie and Cindy also recommend using matching thread in your bobbin.
The quilt will tend to get a bit bulky as you get closer to completing the project so simply fold it over to make sewing everything together more manageable.