I have been meaning to post about some easy to make bookbinding tools made from book board. Right now my book board comes from upcycled notebooks from the thrift store - if I can find some in good shape. For just a couple of dollars you can make these essential tools. I can't take credit for the design as these are copies of what I remember using in the conservation lab at BYU-Provo. Some other recent blogs that review basic, affordable tools are by the fabulous Karleigh Jae and re:Paper at the Bookbinding Etsy Street Team Blog.
First up is a cutting guide with finger guard. It is about 3/4" wide and is ideal for trimming book cloth. This design is not ideal - the ones I remember had a built up section in the middle that made it easier to grab and hold on to. Still, this works pretty good and I may get around to fixing it. The upright end goes to the outside, facing away from the book to protect your fingers from the blade as you cut.
This is a punching cradle bought as a kit from a book binding/paper store. It is fairly simple and could easily be reproduced. (The kits are no longer available). The white section is tyvek, but could also be cardstock. Over time you have to glue additional tyvek or paper because lots of punching will weaken the join.
Finally, this is what was fondly called the corner-matic in the conservation lab. It is used to cut the corners of book cloth when making up the cover. I think the Banister book has instructions for something similar, but I much prefer this design. This pictures shows the corner-matic face up so you can see how it is put together. To use it, place it face down over the corner you want to trim and you will get a nice 45 degree cut the right distance from the board corner.