Submit your web-pages link only on good PR and good alexa rank site, also do ethical work for your web-page, Hopefully in your PR update your web-page will get good PR.
bookmarking, direct submission, maintenance of the website and unique content)))there are the gold rules of the SEO
You could increase your PR by getting backlinks from authority sites in your niche, the more of these links you get the higher your PR rises given time
Simply put, to get a high PR you must have high PR links linking to your site. If this has already been done then make sure that your link juice is not shared with other sites. Make all outgoing links "Nofollow". Also add "Nofollow" to sites of Social Media. Continue link building and hopefully your PR should rise.