There are many ways to increase the Backlinks. Find a few below:
Directory Submission
Social Bookmarking
Classified Submission
Blog Commenting
Forum Submission
Image Submission
Video Submission
These are some SEO techniques to get more backlink are
PPT submission/Article submission/Web 2.0 submission/Social Bookmarking/Image Bookmarking/Blog Commenting/Forum Posting.
For increasing backlinks, you should have to make the quality back links for your site. By doing off page techniques such as social bookmarking, business listing, classified listing, blog & article submission, guest posting and so from where you can get back link.
With Off page SEO and link building, we have many ways to do, and here i know some ways as listed below:
1. Forum Post.
2. Directory Submission.
3. Article submission (Articles needs to provide)
4. Web 2.0 (Articles needs to provide)
5. Social Bookmarking
6. Search engine submit lac
7. Blog Comment
8. Ping
9. Wiki links
10. Guest Posting
11. Classified Posting etc
I hope this helps.