My take on it is (in order of importance);
1. Keyword Research - to find the highest searched, longer tail keywords with minimal competition.
2. Optimise title tag with keywords
3. Include keywords in the header, content and any alt tags on image - but not to over optimise!
4. Make around 20-25% of links that point to your site the keyword in question.
With regards to wordpress, say I wanted to optimise the words "dog training" but dog training is a category, as opposed to the title of the site - would this method still work?