Not quite DIY as you don't actually have to make anything. More like creatively use inexpensive products! I have make mention in previous posts to a speedlite velcro strap, to which I attach light modifiers. You could go the expensive route and buy a couple Honl "Speed Straps" for your flashguns at $10+ a piece. Or you can "make" one of these:
By "one of these" I don't mean the flash of course.
Extremely simple to do, yet so versatile.
Read more after the jump!