I've been at the stock photography game a while now, and after looking over my sales statistics across all platforms I sell or license my photos and videos through, there are a couple of little tidbits I'd like to pass on to people thinking of shooting photos for Stock Photography purposes. These insights are my opinion and are based solely on my results, taking my portfolios in mind.
First thing is; SHOOT THE PHOTOS WITH THE IDEA OF SELLING THEM AS STOCK PHOTOS IN MIND RIGHT FROM THE GET GO! Really. Shoot them with this purpose in mind right from the start. Don't think too much, don't get too artistic or fancy with them. Get into the habit of thinking of things to shoot that you wouldn't think of taking photos of. I know most people who get into photography want to shoot the next great piece of art and what have you, and yes, that's great, go for it, but for Stock Photography, you have to approach it from a different angle and a dedicated mind set. Think of these photos from a buyers' viewpoint; what do advertisers need? What obscure, overlooked items and subjects are not well represented in Stock Photography outlets? Find these kinds of things to shoot. My most popular photos that I sell are, in fact, pretty mundane objects. Things like electrical power meters, batteries, fire hydrants, industrial waste, and gas meters. Boring right? I know. But you know what? Photos and videos of those things sell REALLY well!
Second thing is; Make sure you frame your objects (or subjects) off centre in the photo so the client who buys them has space to add their text or title or whatever they want to them. Take photos with the objects to the right, the left, at the bottom and the top of the photo to cover all aspects. I have photos of the same objects off to the left, the right and centred, and I can tell you that the off centred ones sell MUCH better than any of the ones where the object is in the middle.
Take a peek at some of my top sellers on Shutterstock and you'll see what I'm talking about. None of these are high art by any stretch of the imagination, but they were shot with the sole purpose of selling on Stock Photography outlets, and I've been very successful with them.