Product Photography lighting.

Here is a great spa theme/aroma therapy image that has gathered over 1084 downloads in about a year. The artist is Lisa Gagne, and the image is from istockphoto.com



Here is a great tutorial for do it yourself product photography.
http://www.jyoseph.com/blog/detail.cfm/post/18
Here is another one worth checking out.
http://www.northlight-images.co.uk/product_photo_training.html
Tip:
One thing I have noticed, if you have white ceilings, think about pointing a light towards the ceiling to reflect light of the ceiling to light the top of the object being photographed.
Continuous Lighting:
Continuous lighting refers to lighting that is on all the time. I have some opus lighting units, so I can replace them with normal light bulbs that stay on continuously. Try this technique if you can. Of course, you will need to use a longer shutter speeds and a tripod because the light produced is far less than with flash units.
Still Life Themes:
If you are looking for themes that sell well, think about spa. Images of candles, flower peddles, herb bottles, etc, etc, are always great sellers. Keyword some of these in istockphoto.com and you will see what I mean.