The optimum length for a title is between 6 and 8 words. Do not repeat keywords more than once. It is also important to use the title tags to draw visitors to you site. Therefore you need to make the text interesting so that visitors will click on your site. We suggest between 10 and 25 words in length.
Many search engines score lower if the keyword is repeated, than for a single keyword.
Make sure your keyword list includes both general and specific words related to your site. It's best to make them plural where appropriate and to include derivatives, since you can't rely on all search engines to account for such instances. Check out this list of the top 200 search words. Often text found in the headings scores higher than text on the page. It is worth taking the time to carefully construct your pages using these tags filled with keywords.