Are most of the boxer shorts printed with an overall design or do they have logo/sayings instead? I think the pattern used would depend on this. If it is an overall pattern, any type of tessilations, 4-patch, or 9-patch patterns should work great.
Since this is for a friend, here is something that will be special for her. Make sure to take pictures of the process as you go. Start with the packages & you opening them up and spilling those fresh fabrics everywhere. You can take pictures of you at the sewing machine making a block, you cutting up the fabric, and basically making a historical journal of the making of this quilt from beginning to the end. You can easily pick up a small photo album from a local dollar store (or WalMart). When you are done with the quilt, it will go to the son but the photo journal will go to your friend (or into your personal quilting journal).
Of course, it wouldn't hurt to take my own advice! :roll: :lol: