The topic of adding image alt tags for effective SEO has been a subject of debate for some time now, especially as it's traditionally been used primarily for visually impaired customers to be able to effectively identify what's in an image via their text-to-speech devices.
However, in recent years, Google and other search engines have begun using this field as an effective way of identifying images to index for certain keywords and topics relevant to the content on the page the image is found on, especially in relation to your product images.
Webninja already automatically applies alt text to your product images - so those are already covered - however what about when you upload images to your custom pages or editable blocks...?
ADDING ALT TAGS TO YOUR UPLOADED IMAGES
You can add alt tags to your images you upload to custom pages or blocks by editing the block or page, click on the image to be edited (eg. social media links in your footer):
If you click on one of the images while in the editor:
then in the menu bar, click on the image icon:
This will open a new pop-up for editing the image - click on the "Image Description" field and type in what alt text you want to use:
Click OK and then save the page or block you're editing - now the image will have an HTML alt tag applied to it that matches what you typed: