As an approved photographer on stock libraries, you can possibly get access to client briefs where you can submit your work direct to the client, meaning they’ll consider you for the project and see your profile. Otherwise there’s usually a marketplace type system for you to upload your images and have them added to collections based on themes, destinations and seasons.
Lyn's last tip is to have your own website. "Show off your work on Instagram and Facebook, but do ensure you have a good, easy to use website too. It should have some of your best work (with lots of keywords!), any specialities, and awards/competitions you have won, and your contact details. It's too easy to get carried away, add thousands of images, and forget the basics. Keep it simple."