Some libraries already have enough travel shots, but the big online stock libraries are always looking for fresh images, and want to offer as much as variety as possible. So, if you want to submit to a particular library, check you have a good range of high-quality images that are different from the library’s current selection (and as good as, or better!). Libraries will also take a cut of the money you make from selling your images, typically 50%.
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."