If someone makes minis, the pieces can get downright tiny. Also the crumb blocks can use some thin strips. For me, the size depends on how much I like the fabric and how much I have left. The more I like it and the less I have, the stingier I get and keep even small triangles.
There is also a technique working with snippets which are truly all the bits and bobs sewn down with threadplay. I toss those in the rubbish bin right away.