I keep 2" and above in one spot and occasionally add to my stash of 2" squares for postage stamp blocks done either random or monotone, then stored for future use. The others are trimmed out at 2-1/2", 3-1/2", and 6-1/2" so I can use them in combo blocks. The smaller strips are saved to use for covering cord of various thickness for coiled baskets, mats, etc.
I don't waste a whole lot for the very reason you state - lots of coins going in the basket if not used.
Scrap cutting day is when I need a complete diversion from whatever, i.e., a real no-brainer. Just make sure you're cutting on the weft or wale (cross or length). It's easy to cut a square out of a wonky scrap on the bias which doesn't work too well. Just a little tug on the piece will tell you.
Sometimes I like the scrappies better than the original piece from which they came! And I feel ever so frugal in the process.