Audience quest: Pay attention to what your audience is asking and give them what they are looking for in your blog. Whether it is content or questions, make it interesting.
Grammar - Depending on the language you use, blogging just makes it imperative that you are reasonably good with your grammar skills and proficiency if not a master. Remember your audience is a mix of both; the ones who are experts and the ones who are not.
Post Ideas: At times you will just run out of ideas for post not sure what to do. use google and apps like Evernote to note down all that ticks in your mind. Something will surely turn into a new post.