best method to make paper in minecraft?

if you need a lot of it, put an observer facing the cane with a piston behind it at the second block height. every time it grows the piston knocks it off, hoppers underneath, and you stop thinking about paper.

three sugar cane in a row in the crafting grid gives you three paper. any row works. if you're short, plant it on sand or dirt with water directly next to it and it'll keep regrowing.