It would all depend on what future projects you want to work on. Currently I am wanting to make a scrappy Log Cabin quilt so I am cutting my scraps into 1 1/2" strips by 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, 7.5 and 8.5".
If you have some patterns that you want to try that use squares, by all means cut into squares.
I have a tendency to let my scraps really accumulate.