Be clear about your goals for blogging. Maintaining a blog is laborious. And your goals will keep you motivate!
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.
Write guest blogs for others and have guest bloggers on your blog to increase your audience.