Write guest blogs for others and have guest bloggers on your blog to increase your audience.
Presentation is as important as good content. Have attractive pictures, fonts, etc. on your blog to hook the reader.
Add your personality - If you are writing on a particular topic, there are a number of people who will be writing on the same topic. So you need to add that specialty to your blog to make it look different and to allow your readers to take away something that the others are not offering.