Content is the king - In the blogging world so diverse and big, you need to establish yourself with a distinction. the only road to it is good, original and valuable content. Be creative, different and surprise your readers once in a while.
1 per day: If you have just started blogging, then writing consistently might take time. So set a target to have 1 post per day that is well researched.
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.