Okay. You asked for it. Click pictures to see larger.
5 peices of foam core board. (about $1.50/sheet at Walmart).
White or light colored tape (I used white duct tape).
1 poster board ($0.39 at Walmart)
2 lamps, just about anything will work, with bright WHITE light bulbs. These can be light you have around the house.
Step 1. Get someone to help you hold the foam core and using tape, tape the OUTSIDE of the box together. Duct tape works great for this. You will notice that the two side pieces are sticking out from teh rest of the box. I scored these (box cutter lightly over it) to use them as flaps on the front. You can cut them off if you want. I thought it would be more surface to bounce light off of so I kept them.
Step 2. Use some tape to put up the poster board against the back. This give you a seamless white background. Posterboard comes in a variety of colors so you have lots of options in backgroud colors.
Step 3. Light up your box with whatever lamps you have around (with WHITE bulbs) or purchase a couple table lamps (the ones with the moveable arms would be best). Place them int he box pointing up or against the sides. This will flood light into the box. If you point the light directly at the object you may get glare. Play around with this. After changing the lights, trying now flash and with flash you'll find the setup you like the best. Happy shooting!
Below is a picture of 2 binderclips that I took in my lighbox. Click to see larger. Please let me know if this tutorial works for you and if you have any other questions. :) I hope this helped.