My take on mounting a softbox, no modifications necessary. You just need two hardware store clamps and a tripod with a quick release slot:
|IMAGE IS A REDIRECT OR MISSING!|
HTTP response: NOT FOUND | MIME changed to 'image/png'
It's a softbox meant for a monolight, clamped it onto a tripod with some clamps from the hardware store (one clamp to hold onto the speedring, one clamp to hold the first clamp onto the tripod-- the arm of the clamp fit into the quick release slot so it didn't really move side to side), and I held my flash onto it with some rubber bands. The third clamp at the top of the softbox ring provided extra tension so the flash wouldn't fall down, but you could replace that extra clamp and the rubber bands with ball bungees (I didn't have any at the time).