Originality - Focus more on the originality of content and on a consistent basis. It is a habit you will need to cultivate.
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.
E-commerce bloggers must carefully write keeping their audience in mind. Everything you post on your blog will speak for your product or service. Your interaction with bloggers in comments and otherwise will give you a direction.