These are some tips to improve page rank
 

1. Update your site regularly
2. Link to your website from other sites
3. Give away content
4. Link to authority sites from your site
5. Write link bait
6. Forum Posting
7. Blog Commenting
8. Directory Submission
9. Article Submission
10. Social Bookmarking
11. Effective content of website
You can also use some technical way to increase page rank. Use Search Engine Visibility service at XnYnZ.com ,here the service helps to increase traffic and page rank of your site by submitting it in many search engines and directories, also generating many Google keywords etc.. I have used these methods to get quick traffic,page rank for my site!