Tip #1 – Alt Text:
Specify a clear and human readable name for your image.
Tip #2: File Name:
Avoid upload images named as “IMG-0123.jpg” people won’t be looking for that kind of names, instead put a consistent title and related name to the image you want to show e.g. (my-cat-playing.jpg).
Tip #3: File size:
You may have heard about different image extensions but be sure the images you upload to your site are exported in any of these formats (jpg, png or gif), jpg is the most common format followed by png with a difference that this one allow transparency and last one is the gif that are mostly use for animated images.
Tip #4: Caption:
Provides a extended information or better description of the image.