Look through your stats and figure out which keywords work best on your blog. Which search terms are people typing into search engines to get to your site in the first place. This is an important thing to know if you are going to get more readers to come in from search engines.

When you know what people on your blog are looking for, you can write blog posts based around those search terms. You can also go back and optimize blog posts you've already written about those topics. This will increase the ranking of those pages and bring you in more readers.

If you don't have stats for your blog, consider using Google Analytics. They have everything that you need to keep track of your stats.