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.
Use technology - Social plugins and SEO tools are a great thing to market your blog or a blog post. If you do not know about it, then learn it. It helps you reach out your audience in a better way and also improves the ranking of your blog.
Build a community - Connect with like minded people/readers to know what they expect out of you. Interact with them at regular intervals and take their feedback. It will help you gauge a trend and hint you towards a direction you want to take your blog to.