Alexa rank is calculated by the traffic you recieve.

First register your site in alexa.... then drive traffic... install alexa toolbar in your browser and visit your site regularly.......

You should hire some expert on seoclerks, then your work will be done by an experienced person.

Alexa rank comes from traffic. If you get traffic to your site you will boost your rank. So the question is how do you get website traffic? It is gradual process, comment on blogs, submit your site to directories, write articles etc.

Alexa Ranking is totally depends upon the number of visitors to your website. To increase the visitors you have to promote your website.