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 something useful for your readers. Share a relevant piece of information, an event update or a hack that makes a task simpler
Tags: Use of relevant tags is important from the SEO perspective. It helps the search engine track your post based on the tags you use.