Use any paper that isn't magazine shiney: tear into small pieces (get the kids involved) mix in small amounts of water until a runny paste is achieved (yes at this stage you can ad a little bleach or hydrogen peroxide for sanitizing, but why?). Mash the mess with a potato masher until it is thoroughly smashed to mush.
It should be sloshy pourable as you set it into raised window screens; off the windows works best, laid flat. Use a stick or spatula to make the sheets as thin as possible. Sun or shade let it sit until set.. then let it sit some more. You can flip the paper when it gets dry enough.. or just let it be.
Remove from screens when dry, if tough, work it by gently rolling it.
This doesn't cut well, but you can tear into more manageable pieces. It will probably be gray with small bits of red or yellow paper.. this doesn't matter as what you are going for is a spongy softer than a plant leaf texture. You can vary your paper recipe ingredients to achieve this, and if you don't like the texture, you can put the potato masher back into use again, just treat your paper like paper and shred it into a slurry and start again.
You can do this in a blender with harder cardboard type papers, but single sheet paper works well such as phone books, catalogs, magazine circulars anything that doesn't have a shine to it. Remember, if there are sharps rough parts in the paper, then there will be sharp rough painful parts in the paper. I have heard you can do this with various other items such as pussy willow (?), woody pulp from friendly non allergenic plants, corn silk (but it can itch), try it out and then try it out.
In times of travail, TP can be a nice gift or trade item, and these are tough enough to be used over and over again, before they are used as tinder to the refuse pile fire.
When reduced, Reuse Recycle..