Seems to be an impossible task! Most of my works are isolated objects. So it is very hard to get in iStockphoto. Could you please comment about these? Thanks.

http://www.bdspn.com/Istockphoto/Button.html

http://www.bdspn.com/Istockphoto/NaturalSoap.html

http://www.bdspn.com/Istockphoto/Grasshopper.html

Nothing wrong with these technically as far as I can see.
Now the bad news. Sorry. The button shot won't get you in. It's not really "stock"and has no real concept. The soap shot, not immediately obvious what it is, again it won't get you in. Grasshopper, might possibly be OK, although I have the feeling that nature shots might be tricky for application.

To get into iStock these days you really need to show a variety of types of subject and technique. You also really need to show that you have some idea what stock is about. As an example, you might submit a shot of a person, or people doing something. A still life, preferably with some sort of story or concept, and a landscape.

If I had to apply now I'd shoot my application shots particularly for iStock, and pay special attention to the details.

Thanks Difydave.