So it's important to read each agency's requirements before you submit photos to them. That way you won't waste their time or yours.

There are two things to keep in mind when submitting your photos for review: Title and Keywords. Choose as descriptive a title as possible for each of your photos as it'll help prospective customers identify the subject of the photo more easily. The other thing to think about is keywords related to the topic of your photograph. These are used to match the search terms entered by customers for photos matching what they're looking for. So the more keywords you use, the better your chances of your photo appearing in the search results which, in turn, increases your chances of a sale.

Selecting keywords can be difficult. A little lateral thinking may be necessary to come up with alternatives. Suppose you've taken a picture of some trees. What keywords could you use as well as the obvious "trees". Well, there's "tree". If it's a small clump of trees you could use "copse". If it's in a forest, you could use "woods" and "forest". Trees are made of wood, so you could add "wood" and "timber". Trees have leaves, so another couple of keywords are "leaf" and "leaves" (always use the singular and plural versions of a keyword to increase the chances of your photo being seen).

When was your photo taken - include the season, such as "autumn" or "winter" as a keyword. If the trees were covered in snow, you could try "Christmas" or "holiday season" as keywords. Keywords don't have to be single words, they can be phases as well. If there's fog or mist in your trees photo, another keyword might be "enchanted forest". If the photo was taken at sunrise, you could use "trees at sunrise".

Ok, so your photos have been accepted, now what? Well, that's down to a couple of factors - current trends in the type of photos that are being bought, how often your photo gets seen and how it meets the needs of prospective customers.

Don't expect to see your photos selling like hot cakes! You might be that lucky, but it's not likely. Stock Photo agencies contain hundreds of thousands of images. Most agencies break their photos into categories for easier identification. But that can still mean your photos are up against several thousand or tens of thousands of images in the same category.

At the very least, you can use the submission process to get an objective opinion on your photos. Where else are you going to have professionals review your work for free? A reason for rejection will usually be provided when photos are turned down. So you can use this process to refine your photographs - either through improving your techniques (because you'll be told what you've done wrong) or in better identifying the kinds of photo that appeal more to people.