Post Ideas: At times you will just run out of ideas for post not sure what to do. use google and apps like Evernote to note down all that ticks in your mind. Something will surely turn into a new post.
Series of articles - Create a series of articles on your blog if the subject you choose to talk about is an extensive one.
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.