I have drawings that are 20 and 30 years old still laying around XD
Well, idk really. I mostly just draw on normal paper, and if I like it, I keep it, if not, I just throw it away. In the end, I usually just keep anything I found to be well made, or at the very least a little bit interesting to keep, even if it's a bit ugly or something. But then again, I am a little bit of a hoarder, haha. I keep most stuff in boxes and stuff tho, and the boxes stashed away, so the space itself isn't a problem for me. At some point tho I will probably throw away more of it.