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.
Recommend content is advisable for E-commerce bloggers. For e.g. Recommended books. A buyer will want to know what more is there in store for him/her.
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.