Write regularly; not too often or too rarely. Two to three blogs a week is a good frequency to maintain. Depends on the genre though.
Incorporate gadgets and widgets on your blogs so that people who drop by your blog can keep a tab on what you will be writing next.
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.