Keep your posts simple! Do not try to impress anyone. be yourself! Visit other blogs which might interest you, take part in conversations or simply put your two cents for others to read and follow you back to your blog.
Always acknowledge a comment on your blog and respond to the commentator, preferably at his own blog. Its great to reciprocate the gesture.
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.