Images remain one of the easiest wins in on-page SEO, and one of the most commonly half-finished.
Name Files Before You Upload
A file named "IMG_4021.jpg" tells a search engine nothing; rename it to describe the image before it goes live.
Write Alt Text for Context, Not Keyword Count
Alt text should describe what's actually in the image for accessibility purposes; a natural description that happens to include a relevant term outperforms a stuffed one.
Compress Without Wrecking Quality
Large, unoptimized images remain one of the most common causes of slow pages, so compress before upload rather than relying on the CMS to handle it.
Next step: Use the Page Size Checker to see how much of your page weight is coming from unoptimized images.