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.
Courtesy costs nothing. Be polite when interacting with fellow bloggers and your readers and your courtesy will be visible in your writing.
Bloggers are writers. Even if you're into photography, video making or sketching and drawing.. and are blogging about those skills, you need to write well.