No discussion on image best practices would be complete without addressing attribution: the act of publicly crediting the source of a creative work. Depending on the photo you’ve selected and your own brand standards, you may or may not need to give credit. For example, the CC0 version of the Creative Commons license — which some free stock photos use — makes attribution optional.
Be sure to check the requirements for each of your chosen images, but note: it’s always a good idea to include attribution, required or not. It’s a respectful gesture to your fellow creators of course, but it’s also a means of mitigating usage/rights concerns.
There are a variety of ways to display photo credit, and again, it depends on both what’s required and what’s preferable — for you, for the source, and for the platform. Unfortunately, it’s all a bit of a gray area, due to the rapid change and expansion of digital media. It seems the safest bet is to let the copyright on each image be your guide. Do your best to meet the listed attribution requirements for each individual graphic, even if that means switching up your own preferred attribution style from piece to piece. (Note: this is not legal advice, and should not be interpreted as such. Always check and stay updated on attribution rules for any sources, sites, platforms, and channels you use or post to.)
For affiliate-related images obtained through the means listed above as part of the Associates program, using the provided links serves as attribution on your own site. For social media, you must additionally disclose you’re using an affiliate link.
There’s clearly a lot to know and keep up with when it comes to properly using graphics in your content. Luckily, much of it is common sense, or will at least quickly become second nature as you consistently follow image best practices. And of course, you can always come back to this article for reference!