Cut two identical pieces of cardboard for front and back of book. Pieces may be cut into any shape, but a rectangle, the same size as the paper is easiest to work with. Or a simple shape that has straight edges and is not too jagged (like a coffin, as opposed to a heart) is also easier. Curved edges may be used, but it is more difficult to make the fabric lay flat.
If needed, cut the paper to the same size of the notebook, or very slightly smaller, if desired.
Lay the fabric wrongside up and lay the cardboard, one piece at a time, on it and cut enough fabric to be able to wrap the cardboard like a present, making sure the cardboard is fully covered on both sides. Next, carefully wrap the cardboard with the fabric, placing the ends on the sides that will face the paper where they won't be seen on the outside, and glue in place. It is best not to use too much glue or lumps may form under the fabric. Tuck all the raw edges under, and glue them flat, making sure the glue doesn't show on the outside.
When the glue is dry, decide how many holes you want to hold the paper together. It is best to line these holes up with existing ones in the paper. Using a holepunch, or other sharp object, carefully punch small holes through the fabric and cardboard, making sure they will fit under the lip of the grommets, and that the inside of the grommets will fit inside the holes. Using a tool for grommets, place the grommets into the holes and close.
Place the paper between the two velvet boards and thread the cording through the holes, alternating sides. Tie a hole in each end, making sure the cord is loose enough to open the book but also that it is tight enough that the pages won't slide around.
Picture of my notebook