First thing you need to realize, is that we are not mind readers here. What is the name of your site so we can look at it? Go to aboutus.org and enter your domain name. It will give you advanced reports on your title, meta tags and seo.
Just do the SEO technique ON and OFF Page Optimization It will help you increase your alexa and at the same time your PagerRank will go up also.
Alexa = the toolbar = get people to use the toolbar to access your site. PR? Who cares. Just focus on building fresh links to your site, and increase the content flow.