Remember that if you use some of the precuts to make a patch, you will have to recut some of the others to fit. For instance, if you take 2 5" charm squares and make 2 HSTs, they will then be 4.5". If the pattern also uses 'full' squares, they will need to be cut down to fit.
The only pattern where you aren't recutting would be just squares joined together or a jelly roll race. I really like Pat Speth's Nickle quilt books. She uses 5" squares. Yes, there is recutting, but the patterns are lovely and easy to follow.