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.
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.
Originality - Focus more on the originality of content and on a consistent basis. It is a habit you will need to cultivate.