(1) Initially you can add search engine friendly theme with less image and your choice of image can go for logo, banner and bullets. Try to reduce code size and bytes.
(2) Install “All in SEO” Plugin“. Activate and edit in options according to your visitors focus
(3) Most importantly do add alt attribute for logos and banner, i see most of the blogs miss to implement this technique or alt attribute are not unique. To solve this you can try “Custom Header” plugin and enter HTML codes for each posts and pages