Define key phrases for each site and target key phrases that are actually reachable with the resources you have. This could be 3 terms or 20 terms, depending on the nature of your site. This usually is around 5-10 primary phrases. If your site already has search engine traffic, focus on the phrases that you are already being ranked for to improve SERP.

Use keyphrases regularly in content, page titles and the url especially anchor text for back links. Keep it natural, though. Don’t SPAM your key phrase everywhere, and make sure to include lots of other natural content and words that are contextually related.

Publish new content regularly.

Optimize your url’s. Get rid of dynamic id’s and sessions, and include page titles and keyphrases in url’s.

Obtain relevant, natural back links from authoritative sites. This means finding links on relevant Web sites with good PR, traffic, age, popularity, etc. Let me stress relevancy again. Relevant links are important to SERP’s, so if you’re optimizing a ring tones web site you probably shouldn’t seek out links on say, knitting forums. Links from a content-rich section of a site are better than areas saturated with links, like a list of links in the footer of a site. site wide links increase link popularity but need to be complemented with homepage/single-page links. A good mixture of both is best.

Deep-link URLs. Obtain back links that link to individual pages in addition to links pointing directly to the home page.

Be consistent with URL usage. Don’t link to ‘http://www.site.com/’ on one page and ‘http://www.site.com/index.php’ on another. Pick one and stick with it.

Reduce link clutter. More outgoing links on your page will not reduce your own PR directly, but it will reduce the PR a link can pass which translates to less PR passed back to your own site indirectly. Also remove any unnecessary internal links, with the exception of having 2-3 links for top-level pages (such as in the header, menu, and footer).

Use free SEO tools available on the internet and pick the ones that meet your website’s specific needs. Regularly analyze and improve your own strategy, and monitor results in SERP.