I have a small binder that I document all of my loads in. I really should have one for each rifle but so far I don't.
When I shoot the targets I document on the target what the loads are (as you are doing). I then document in the notebook what results I got (at home). If I'm working a "ladder" I make sure to asterisk the load and then put everything I can on the same page.
Most of the targets get tossed after a while but I save them in a stack for a few months because sometimes I want to go back and rethink my load scheme.
I've scanned some of the better ones but mostly to brag. layback's idea of scanning them all is probably a great idea.
