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.
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.