I like to cut 2 1/2" and 4 1/2" strips and 2 1/2", 4 1/2", 6 1/2" and 8 1/2" squares because these are sizes that I can and do use for my scrap quilts. There's no point in me cutting 1 1/2" strips because it is just not a size that I am likely to use. You need to know what will be the most useful for you otherwise you might just as well leave them as uncut scraps to use at a later date or to pass on to another quilter.