Image speak - A lot of bloggers tend to ignore this, but the images on your blog speak a lot for what you write. Use good quality images and make sure they express your written stuff in utmost simplicity yet precision.
For E-commerce bloggers, it is essential to define your audience and take worthy steps to reach out to them. This will be the sole determinant of your marketing plan.
Originality - Focus more on the originality of content and on a consistent basis. It is a habit you will need to cultivate.