The most important aspect of Search Engine Optimisation is visible text. The combination of well written text that is meaningful, informative and heavily weighted with appropriate keywords is the safest and most effective method when constructing web pages.
Each page of your website should be dedicated to a specific topic. The text on the page should be built around two or three keywords or key phrases.
The text on the page is the most important factor and while it needs to be weighted correctly with keywords, the readability for visitors is still more important. There is no point having a great deal of traffic if the text is not well written, alternatively there is no point having the greatest piece of text if nobody reads it. Therefore the best approach is to write the best text possible with keywords in mind and then review it at the end for further keyword additions where it suits without damaging the effectiveness of the text.
At ANSO text content and keyword weighting is at the forefront of our minds when developing a website. On-page search engine optimisation should be as much part of the over all development as the layout of images.
Don't be fooled into thinking a pretty website is an effective website. A properly designed website will have absolute methodology to it's design and functionality to maximise it's intended purpose.