What size "scraps" do you keep?

I'm sorting my fabric at the moment. I'm trying to work out what size to keep and when to throw! I made a pouffe last January and any smallish scraps from cutting have been going in there. It's nearly full, I might need to make another one for this year :) But what are the smallest usable scraps for Oliver and S sewing? What pattern? I'm thinking Puppet Show Shorts and maybe Swingset Tunic? In 0-3m size? What size pieces do you keep?