Great article, and here’s a hot tip for you.
Google provides an outstanding image search tool that allows you to filter for images with Creative Commons licenses. After you do a Google search, just click on the image tab, then the tool button and select Creative Commons.
Not only will you get image results from the popular free sites like Pexels and Unsplash, you’ll also get hits from Wikimedia Commons, Flickr, and a ton of other sites you’ve never heard of.
I very much try to avoid the big three free sites, because of how popular they are. Dynamic images are very important, but so are images that are not overused.
It’s almost a sure bet that if you use an image from Pexels, a dozen other Medium writers have already used it.
That can sometimes cause confusion and lack of interest in a story.
For me, using the Google image search tool has made finding great images a lot easier.