I am a fair newbie to the idea of stock photography. The hardest part is initially understanding what the stock libraries want (and what they don't) and then getting my rejection rate down from 70% of submissions without my sanity slipping. I have slowly grasped the concept that stock shots are like no other - it's not so much what you want to shoot, but what is likely to sell. Repeatedly.
I now have around 500 images on line - many salvaged from the cutting room floor especially for the purpose, and some of my best sellers are (in my view) very ordinary snaps I snatched with a sandwich in one hand, a can of coke in the other, and a labrador tugging at the lead wrapped around my ankle. How they came out reasonably focused and pointing in the right direction is beyond me - but somebody likes them.
My most downloaded image is Belfast Titanic museum, sold 5 times now, so someone likes it. Closely followed by this one of Bradford.
Both totally different types of image to most I like to use on my website.
Contrast my meagre offering to other photographers with 30,000+ images on stock sites. I ain't going to get rich, and to be frank, I have better things to do, so I'll just plug away from time to time, when I get a mo.