The title tag (the description that appears on the top of the browser) of your site is one of the most important factors determining the search engine results position (SERP).
There are two common mistakes, however, the people commit when creating the title tag. The first one is to use a single title, usually the blog name, for all the pages throughout the site. This must be avoided because the title of a page should match the content inside it.
Suppose you are using the title “John Doe’s Blog” on all the pages. Even if you have a post talking about “The New PlayStation 3? the title tag for this post will be “John Doe’s Blog”, which is not very effective (because there is no match on the keywords). A much better title would be “The New PlayStation 3”?, that is exactly equal to the post name rather than the blog name.
The second mistake that people commit is to include too many keywords on the title tag, hoping that search engines will take all of them into consideration. Have you ever seen a title like this: “Tech Blog – where you find resources for blogs, websites, technology, internet, applications, software, hardware, and pretty much everything else!”
This should also be avoided because search engines put a value on title keywords depending on the total number of keywords. The result is that the higher the number of keywords you have on the title the smaller the value that will be attributed to each one of them.
A good title tag, therefore, should be short (no more than 4 or 5 keywords) and pertinent to the content inside the page.
Update: You can find the actual code I use on the article “Optimal Title Tag for WordPress“.