Formatting - Your post need not be a circus. If you are not good with formatting, then stick to a theme that is light and descent in colors and the post layout. If you are good with trying new stuff then use that skill to better express through colors, fonts and layouts. Avoid colors that are dark and fonts that are overtly bright.
Share your personal experiences on your blog occasionally. It makes your posts more real and helps your readers connect with you.
Broken links irritate visitors and can badly affect your ranking. Check and repair all such links on your blog.