Step 1
1. Lay the boxers out, fly side down. Cut along the back seam until you reach the center
Step 2
2. Cut along the center seam, perpendicular to the cut you just made.
Step 3
3. Lay them out completely flat, wrong-side up. Iron the boxers. On both sides, fold the waistband over about an inch, pin and iron again, and sew a quarter-inch seam on the outside edge. A quick thought here: check and see if your shorts are too big in the waist for an apron. When you wrap them around your wasit there should be some open space in the back. If they are too big, no problem -- just fold over more than an inch in this step, and trim some of the excess.
Step 4
4. On the bottom, fold the excess up and under (the photo shows it on top so you can see what gets folded). Sew a quarter inch from the edge on the bottom, and all the way up the unsewn side to the top.
Step 5
5. Fold the shorts in half, wrong side out. Pin and sew a straght line from the bottom of the fly to the bottom edge. Trim the excess.
Step 6
6. Choose a ribbon, about 2 feet or more for each side, depending how long you want your apron strings to be. Fold one ribbon end under, and sew fold to the waistband.