SEO to increase the number of unique visitors on our web site

We have a mature website with 1000 unique visitors per day and a well defined content. We want to increase this number to 2500 unique visitors per day (according to Google analytics), NATURAL traffic, NOT FAKE. The traffic should be relevant for our web site's content (the bounce rate should remain as good or better as in the present). The methods you use to bring traffic should be completely manual: ANY white SEO is accepted (web site submission to forums, improving keywords and content, etc.). Please give us a complete plan on how you intend to bring the required traffic. We pay 220$ for this job. You should accept this project only if you can do it. If you cannot bring the targeted traffic, please don't bid. If you are serious, and the job is done well, we can continue this project for a much better wage.