Avoid use of unnecessary images on the website as they increase the load time of the website and make the website bulky.
Use 'Alt' tags
A Search Engine Spider is not smart enough to determine what an image is about. To help the spiders by providing additional information from your website that they can index, include an 'alt' tag for each image that you use
Don't forget that visitors are coming to your website to take some information. And for providing the required information to the visitors, search engines crawls your website. The ultimate main purpose is to provide information to the visitors. So keep your website more informative and post content on the website that is relevant to the site.