i would cut the squares 1/2" larger than the measure you want to end up with. cut all the good parts of the material and set the blocks aside. get as many as you can. when you can't go any further, start laying them out. the quilt will tell you what to do. you will probably need a color that you don't have enough of, but the quilt will tell you. that will be the color you may have to buy. it may be different for each one.
post pics as you go. you'll get more advice than you bargained for! hee hee!
LOL