I’ll share my experience with sketchbooks.
I’m afraid I’m not one who has ever been able to get the hang of ‘letting go’ in a sketchbook. It appears I’m too anal to truly experiment in anything I plan on keeping. Still, I do like sketchbooks for the simple reason that it keeps things in one convenient place and also if I want to draw at work, on a plane or in an airport, etc
So the system I’ve arrived at is to have two sketchbooks— (1) a good quality one where I try to have finished products, to the point of covering up failures with something opaque and trying again, and (2) a REALLY cheap sketchbook which doesn’t even hold together and has such thin and crummy quality paper that it’s almost impossible to do a drawing worth keeping, then plan on throwkng it away even if one of the drawings works out (which I’ve held to).
The downside of this system is obvious.. it’s sort of self defeating to use crummy materials.. yet Personally, I guess I’ve done enough things in life to have come to the conclusion that sometimes it’s better to work with your own nature than to run against its grain.