Take the sheet of paper and fold it in half. Make sure there are no unequal corners. Fold the sheet in half further in the same way, while making the paper shiny, using the bone folder or tongue depressor - a bone folder will ensure the paper does not get out of shape.
Fold the paper twice more and unfold it all the way back to its original form. You will notice that the paper now has equally shaped sixteen rectangular boxes on it.
Cut the sheet in W shape. Use the top layer of the paper and flip its edge back to meet the fold and crease. It is better to cut from the right side and reach the first left fold to make book-like shape. The W-shaped folds will now look like pages that you can turn over.
Take two pieces of cardboard, and cut them to size ¼ inch. The cardboard pieces should be bigger than your book.
Stick the cardboard to the outside of the book with glue.
As soon as the exterior of the book is assembled, press with something heavy and leave it under it a few hours, letting the glue dry.
Your accordion book is complete now. You can write anything on it and give it to your kids or friends as a gift.