Excellent Creative Commons images on Pixabay
I do a little bit of graphic design, and often I find I need just a background image of some type. Often I'm building a banner highlighting one of my wife's new books - so often the image is not central - it's just to set the right tone (at the beach, nature, sunshine sunset, etc). I often don't need the "perfect" photo - heck often I use vacation photos that I've taken myself if they work - but sometimes you need a pic of somewhere you've never been - or just an artistic abstract background.
Anyhow, a website that I've found very useful is Pixabay . This website contains some very high quality creative commons licensed work (usually CC0 licensing which means you can use without worrying about licensing restrictions) and the site is searchable and easy to use. And Pixabay is not just for background images. If you need an image that sits front and center - you very well could find something here - although anything with peoples faces/expressions is going to be in short supply - likely due to the legal signoffs around using photos/likenesses. Still - very useful site with great pictures.
I've uploaded some of my own photos there for usage (my photography isn't the best, but it might be helpful to some folks). Several of my submissions have gotten rejected, so they just don't take any old photo - so only the good stuff makes it onto the site. For folks like me who want a community to contribute to as well as be able to use a few photos for what little graphic design uses I have - Pixabay.com is excellent.
Here's a few pics I've uploaded to the site
Cicada Shell Macro
Cool Flower and Butterfly Tongue Macro
A Wooly Worm Macro