Velcro, and some sort of stiff, but bendable translucent plastic. Look at a hobbies and crafts store for the materials.
Tried messing around with a couple different things last night (tissue paper, etc.), and the flash dimmed a great deal. That was using ETTL, so obviously the camera didn't know that there was a diffuser on the flash. How can I compensate for that? Would I have to go totally manual on the flash controls? I don't know my manual controls very well, but I think I had it set at full flash and it still was very dark, even with just a single piece of tissue paper over the flash head.
With any flash modification, store bought or DIY, you'll probably have to run the flash on manual. If you don't have a flash meter to measure how much you are reducing the light by, you'll either have to experiment until you figure it out, or use a manufactured softbos/diffuser/whatever... that comes with instructions telling you how much to compensate.
Just pick up one of these. They should only be around $20-30. http://www.lumiquest.com/lq925.htm I think the 550 has problems with having modifiers on it and working with ttl. I believe it only works in aperature priority that way. Its been a long time since I had to deal with that issue.
