This is a core skill in bookbinding – covering a hard board with fabric or paper to get a neat and professional finish, which can then be used as a cover.
Practice with a single board that could be used as a cover for a zig-zag book for example. The method for doing the turn ins (borders or “hems”) and corners is the same for most hard cover structures so these are useful skills to perfect.
A few simple hand tools will make the job easier: A decent brush to glue with - flat ended bristle brush that you can "stipple" the glue on with is best. Supplier A bonefolder with a pointed tip - essential hand tool for bookbinders. Like this one Corner cutter - make your own and you will be amazed at how useful it is. You will also need scrap paper to glue up on, PVA glue, a sharp blade (scalpels are the best), a metal ruler (2 or 2.5cm wide), cutting mat, some 2mm grey board cut to a rectangle and something to cover the board with. The grain direction of all papers and card should run head to tail.
Video: covering the board part 1
Video: covering the board part 2
