Here are three simple steps of the SEO equation to remember: 1. Choose to target search terms that convert prospects into customers and make sure there is room in the market for you to gain a Top Ten ranking in 90 days or less. 2. Optimize your page content and HTML code for those terms. 3. Actively seek external, one-way, incoming links with variations of the targeted key terms as the anchor text. Most Webmasters make a key mistake in not testing their researched keywords to make sure the visitors targeted actually convert. So, they end up with good traffic but no buyers. Test your keywords through a PPC campaign first before you ever spend time optimizing. Now for a list of Don'ts * Don't bother optimizing a page that redirects. Don't use Meta Tags that block or impede a search engine spider's access to your optimized pages. * Don't use same color text and background. This makes the text look invisible to the visitor and search engines view it as "Spam". * Don't Spam keywords with immediate repeats. * Don't force any text to appear at 4px or under. * Don't use frames. * Don't fill your pages up with internal scripts. Where possible, use links to external scripts.
Some good basic tips there. I'll second your one on testing on PPC first . . . makesure you know there's money in a term before you spend time and effort on SEO . . . it only makes sense!
There is a keyword tool from MSN which can help web masters determine the commercial intention for each keyword. Those keyphrases with a high figure are more likely to convert.