Search engine optimization requires a lot of on-page and off-page optimization techniques and activities, but I will discuss only about the content related portion of it, that is, on-page optimization that you can do on your webpages.
Finding the right keywords and optimizing your website for them
The first step is to select the right keywords. Think of the keywords that your prospects will type on a search engine like Google, Yahoo, or MSN. You also need to do competitive analysis to find out the most popular keywords, and keyword competition. A perfect match would be to find a keyword that is popular and has somewhat less competition. In other words find keywords that have high demand and low supply. All the important keywords and keyword combinations should be placed in the meta tag keyword tag.
Title tags that bring traffic to your site
Title tag is the most important tag of your page. The length of title tag should less than 60 characters or 8 to 9 words. Ideally the keyword should be used in the beginning of the tag. You should not use the keyword more than two times in the title tag. Use keyword combinations in the title tags.
Meta tag descriptions to attract visitors from search engines
This tag appears in search engines results page so it should be compelling enough to make the visitor click on the website. The keyword should be used in the beginning of the tag and should not be used more than twice. The length of the meta tag description should be less than 125 characters or 18 to 20 words.
Using descriptive H1 and H2 tags effectively
H1 tag is the next important tag after title tag. The keyword should be used in the beginning of the tag and it should be compelling enough to make the visitor read the rest of content. Your content should have lots of sub-heading too. Make sure that the headings are informative rather than vague and convoluted. Avoid fancy language; be direct in headlines of your page.
Optimizing body content to the fullest The keyword density in the main body text should be around 2 to 4%. There are many free websites that help you in measuring keyword density of your webpages. The keyword should be used in the opening paragraph and in the opening sentence. It would be a good idea to use the keywords heavily in the opening paragraph, but do not overdo it in rest of the content. The keyword should be also used in the middle of the content page and in once in the closing paragraph. A variety of keyword variations should be also used in the content and in the h2 and h3 tags.
Providing descriptive link tags
The keywords variations of the targeted keyword should be used in the hyperlinks of the other links in the website. This gives more weightage to keyword density.
Giving meaningful page names and alt tags for images
Usually people ignore the importance of image names and tags, and many a time they have names such as “4768978″ without any tag. Try and use essential keyword in the image name and page name as search engine can read them.