Crafting a block note with draft papers
You can take a stack of paper and press them together between 2 wooden boards, making sure that one of the short sides sticks out a few mm. 
You then cover the side of the paper that sticks out with bookbinders glue (PVA glue) and let it dry before you unclamp the stack of paper. 

You'll end up with a nice noteblock with allows you to pull of sheets of paper out of it but is on the hand strong enough to keep the paper sheets in while flipping through the pages.

I used this when I was a student and used the backside of printed paper from my fathers office.