Decide what you will use to cover the book. You can use cloth or paper to make a very functional book cover, the preference is yours. If you choose paper, make sure that you are using a heavy, durable paper. Many people use grocery bags for this purpose.
Lay your chosen book cover material on a flat surface and smooth it with your hands.
Open the book as though you are reading it and center it on the material. Keeping the book centered with equal amounts of excess paper or cloth on the left and right sides, slide the top edge of the book to the top edge of the paper or cloth. Mark the bottom edge of the book against the excess paper or cloth at the bottom. Use scissors to trim off the excess. The cover should now be the appropriate height for the book.
Use a pencil to mark the ends of the paper or cloth about an inch past the left and right edges of the book. This extra inch on each side will become the flaps that you will use to secure book cover around the book. Trim the excess paper that lays beyond the inch you have measured on each side. The cover should now be the same size as the book with an extra inch on both the left and right sides.
Fold the excess flaps on the left and right inward toward the inside cover of the book and secure with tape. Tape carefully so that the tape touches the cover only and not the book itself.