I love to look at postage stamp quilts. You might try a google search for images of postage stamp quilts and figure out why some appeal and some not so much. The ones I like best have a small element of order or pattern in them. I saw one beautiful quilt that had more reds than any other color, but still very scrappy with lots of other colors.
As remadder suggested if you make blocks of squares you could arrange them as you go. If you have a design wall, you will be able to step back and look at the whole and adjust placement or add colors.