Unfortunately it not an easy question to answer. Not all stock photo sites are looking for the same thing. Here is what Dreamstime.com is looking for straight from their site:
"We are looking for well defined commercial concepts, marketable good compositions with creative insight, high technical level in terms of color, definition, lighting. We encourage digital processing and creativity, as long as it gives the image more appeal, but keeping in mind the generic essence of stock imagery. This is true for the main theme of the image, too. The subject should be as generic as possible, while composition clear, without elements that can distract the viewer from the main theme. We value intellectual creative process which makes the difference between concept and point-and-shoot. One good way to get a better image of what's hot in stock, is to browse through our best selling images. This way you'll get a visual, thus more effective help in understanding and achieving success as a stock photographer on Dreamstime."
Every site is a little different and they best way to figure out what a site wants and doesn't want is to just start submitting. This can be a little frustrating at first. One site might accept every photo out of a batch you submit and you can turn around, submit that same batch to another site and get half (or more) rejected. The thing is if your photos are good chances are they are going to get accepted anywhere you submit them.Here are some pretty safe subjects to shoot that will most likely get accepted and sell (assuming they are quality images).
- Photos of people - I think a lot of new photographers are intimidated by working with models, but this is what can quickly separate you from the newbies.
- Isolated objects - AKA: Images with the background completely removed in Photoshop or otherwise. Isolated objects are very valuable to buyers. A buyer can take your isolated image and throw it on a website or composite it into an image with any background they want hassle free.
- Business & Technology Themes - Images of business people and objects. There is already a lot of this out there, but as business and technology changes there will be lots of room for new creative photos.
Well I hope this is enough to get you started. With a little research its not hard to see what is selling and what you should be uploading. *Hint: If you have an idea for a photo hop on a stock site and do a search for that subject and see what sites have already. There is no point in taking the time and effort to shoot something they already have a million of. It might give you an idea of how to do it in a different more original way.
If you have any comments or questions please email me.