If you're looking to optimise your images with ALT text, it's good to have an idea of how to write high quality ALT text. Let's go through some of the most important best practices.
Try to keep ALT text to less than 100 characters.
Ensure that you describe the image accurately.
Don't include prefixes like "image of," "photo of," or "drawing of."
Don't use keywords if they aren't relevant to the contents of the image.
If possible, provide context to an image. If you're using the image to support an article, try to keep that image within the context of the article.