Photographic equipment such as backdrops, lights and reflectors are really
Here's some 'homemade' solutions:
For tabletop shots:
One of those tri-fold boards like the kids use for science fair projects with a solid color sheet draped over it. Get different colors, and if you can get just the top sheet, that's even better.
For larger subjects:
One of those expanding springy shower curtain rods with solid color cloth shower curtains...again a few nice colors that will compliment your subjects.
The rod should fit right into a average sized doorway allowing you to place the item in front.
Two or three of those round silver jobbies that you can find in a hardware store. There have clips on them so they are portable and can be clipped to almost anything.
To diffuse the light try a regular normal umbrellas placed near the lights *never directly over these lights, as regular rain umbrellas are not fire proof, and those lights to get hot.
Experiment with different bulbs.
Even better lighting if your budget allows would be those tall construction lights.