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.
Its not just good content that matters, presentation of post is very important too. Have attractive pictures, fonts etc to hook the readers.
Follow up on comments you wrote on posts. Continue the conversation. Bloggers enjoy engaging with their readers.