This photo of a radio was taken in a DIY light tent. It looks pretty professional to me! This photo has a white background, but you can have backgrounds in other colors by using colored hard paper as your backdrop, as seen below.
Now, here are the links:
Super Simple Light Tent at Instructables - The Picture above is from this tutorial, this one is very easy to make, using a cardboard box.
PVC Light Box by Bill Huber - Also good tutorial, this one is made by using PVC tubes. It may be a bit more functional as the cardboard frame may cause unwanted shadows.
Tutorial with sound- This one explains the PVC Light Box above, but click on the " the tippin' " button on the menu, there are some good adjustment tips.
I found about these light tent tutorials via Core 77's "Hack 2 School" Guide, which is a very fun and useful guide for design students. I laughed several times while reading it as it reminded me of my college years a lot!
If you can't bother with making one of your own, you can always buy one here, there are many options in a wide price range.
I hope this tip will be useful for you, enjoy!