Why you want to improve page rank?? do you thing page rank will be give you traffic or ranking on search engine?? I don't know why peoples are running behind PR, Just try to concentrate on your targeted keyword and do on page and off when you are doing well promotion your site then PR will be come automatically.
Create some good backlink. You need to bring backlink from High PR sites then your pr also will increase.
Hi, spotlight I think building quality backlinks is always helpful in increasing PR. You might want to get backlinks from dofollow, niche-relative and higher PR sources.
Build more backlinks for your site with the targeted keywords so that your site will rank high in the SERP and the google's pagerank will also be increased.