Step 1. Measure the piece of paper so that you have a 4x4 inch square.

Step 2. Next, cut the paper into a square that is 4 inches by 4 inches.

Step 3. Fold your square origami paper into a triangle by folding one corner of the left side to the opposite corner.

Step 4. Next, make a diamond shape by folding up the right side corner to the top of the triangle.

Step 5. Then do the same thing with the left corner as well.  Crease the folds.

Step 6. Then unfold these corners back down to bring it back to the same triangle shape from earlier. Next, fold down just the front sheet of the paper from the top of the triangle to the bottom edge and crease this edge as well.

Step 7. Fold the right edge of the triangle back up and tuck the end of this corner into the bookmark.

Step 8. Follow the same process for the left edge of the triangle as well.