I picked up this kit a few years back. But, you can use the idea with any piece of Aida. Take any count of Aida and cut a strip of it to fit your design. Make sure that you leave at least an extra half inch on each side.
When you are completed with the design, fold the extra Aida over on each side and stitch. For this particular bookmark, I used the backstitch boxes around the Pooh characters and lined up the holes with those on the back side to tack down the edges. You could also run a backstitch from top to bottom forming a border on each side or use thread that matches the Aida. As a last step, fray the edges on the top and bottom and you have a bookmark.