Some of the possibilities could also depend on your level of patience. There are "portable" lights at the home centers that have spun aluminum shades and some sort of spring clamp that can allow mounting them on {something} perhaps an overhead ceiling joist or a stepladder! They are in the $10 ballpark. You could put CFLs in them to stay cool, or even some of the PAR reflector bulbs for more concentrated light. In essence, the larger the light, the softer the lighting. Scott's ideas for foamcore reflectors are good too.

Sometimes in my efforts to save money, I end up evolving and purchasing new stuff until I've blown off enough money to have bought something really good in the first place. But then if I wasn't sure what I wanted, going to a really "good" thing up front could be wasted money anyway. I consider my trail of idle cheapies to be tuition in the game of life.