Just make a small sample D9P..like small throw size. You can see what you like or don't like about the placement of your fabrics/colors. You can do the whole thing scrappy, and they come out just beautiful. Like with a charm pack...I did that, and it's one of my DD's favorite quilts. Once you start putting it together you will see how it works out.
Another suggestion - cut up some paper squares and put them together like fabric pieces. That may help you visualize.