Start with a square of paper - any size, any kind. Find and mark the center.
Fold each corner to the center point
Open it up and fold one point at a time to the center and fold the new edge to the center line. You'll have to unfold the paper to do this step on each side, because the folds overlap.
On two opposite sides only (I've marked the lines with dots) make cuts along the folds marked, just to the outside corners of the center square.
After cutting, you'll have two straight sides and two triangle sides. Fold the triangle side points to the center, fold the new edge over as you did before. Find the crease on the sides of the folded edges and fold the outer edges toward the center.
Now fold the straight sides up over the ends of the folded triangle sides.
This is how the completed box top should look. For the bottom half of the box, start with a square slightly smaller than the top and repeat all the steps.
My buddy Sharon uses 12"x12" scrapbook papers to make boxes for her Christmas cookies! I miss getting those cookies! I guess she'll have to bring a box to me in Utah!