From childhood we writing on notes and when notes finished then we place notes in shelf. But when you are at heigh heigher studies then those notes are useless for them. We can not write any thing on that notes because we already wrote on it and have no much space to write on it. And we also can not thrown it. Thus how can and where we can use these notes in future?
1.Using a paper cutter, scissors, or a utility knife, cut your paper down to twice the desired size. Fold each sheet in half, and cut your cover material (one for front, one for back) down to the size of a folded sheet. Stack your cover material and pages together and line up all edges. Clip with the large binder clip to secure.
2.Mark 3/8" from both to-be-bound corners (the folded side of the sheets). Divide the space along the binding between these marks into thirds, and mark those locations. These are where we make the holes for the twine binding.
Make holes all the way through the book with an awl, drill, or drill press. If using a drill or drill press, make sure to clamp your papers tightly down to avoid any paper ruffling. Placing a piece of wood under the book helps make a clean cut in the back.
3.Binding in a particular way with the twine and needle. Make sure it's very tight and secure. That's it!
There's a technique used in the old days called cross writing to write new material at a different angle across the existing lines of text on a piece of paper.
A crossed letter is a manuscript letter which contains two separate sets of writing, one written over the other at right-angles. This was done during the early days of the postal system in the 19th century to save on expensive postage charges, as well as to save paper. The technique is also called cross-hatching. - Cross Writing – What Is It and How Do You Read It?
(What they call "cross-hatching" is different from that of pencil artists.)
Here's an example from ritewhileucan.com:
As you can see, it can be difficult to read. Using different colours can help.
If keeping the old notes is not important to you but you just want to recycle the paper, consider using it as fuel (e.g. as fire starters for log fires during winter) or making origami with it.