I use a light box in alot of my shots! I say buy one off ebay! I got a 36 inch by 24 inch lightbox with four color changing cloths for 20 bucks with shipping!
something like this is what i have just bigger!
http://cgi.ebay.com/16-40cm-Photo-S...f#ht_3024wt_941
its worth it man! I built some before and it ended up costing more to build it than to just buy one! when you do build it they end up being flimsy after a while as well! the light tent is pretty much used to filter the light that ends up on the objects you are taking pictures of. So another way is to put a bed sheet or white t-shirt in front of your light source it filters some of the light out but will get hot if left over or around the light for a long time!
hope this helps! most of my crisp shots are using a light tent!
for instance!
http://www.joedios.com/dioramas/sho...&imageuser=3885
cheers! dd