1. Blog Commenting
Aim to make 10 valuable comments per day.
2. RSS Directories
One of the easiest ways to get automatic backlinks.
3. Social Bookmarking
One of the most popular method
4. Video Sites
These days having some video blog posts is a must
5. Guest Posting
You get backlinks in return
6. Internal Links
Internal links from one blog post to another blog post on your site also count as backlinks.
Apply all these techniques together and surely you will have your result