Originally Posted by Maride
I would say, since you don't know what you will be doing with them, cut them the biggest possible. Just get rid of the parts that you know you will not be using, such as seams and pockets (and even those you could use in the future). If you limit yourself to a certain size and find out later that you need just a two inches square but the fabric is not available because you threw away a sleeve, you may end up pulling your hair later. Don't ask me how I know. I say save the biggest possible to expand your future possibilities but also save the little ones for emergencies. You could use baggies to save all the pieces of the same color together.
I agree-I never could figure why people always cut a certain size BEFORE knowing what they will use them for! I wouldn't limit myself that way. I save EVERY scrap because I do a fair bit of applique on my quilts and sort them by color and save them in clear plastic stacking boxes. It won't save time by pre-cutting and you might just find that perfect print you cut in 3" squares is just too small for what you want if for now!