According to Google’s Webmaster Blog

Google doesn’t use the “keywords” meta tag in our web search ranking.

Google employee and general SEO spokesman Matt Cutts released the following video:

According to Matt Cutts, Google (and most other search engines) did use META Keywords several years ago as a factor in search engine rankings.  However, SEO Spammers realized this and would spam the META keywords with unrelated keywords or even competitors keywords in order to manipulate their rankings.  This has been done away with.  Those of us out there looking to rank for specific keywords will have to use legitimate methods.

Does this mean that the META keyword tag is completely worthless?  No.  I actually happen to use it a little.  Many ranking report programs will automatically pull META keywords from the website and use those to check for rankings.  I will add my keywords for just this purpose, even though they have nothing to do with rankings themselves.

Image pulled from http://www.dynamixwebdesign.com

For those who aren’t familiar with HTML, the title tags can be found in the website source code header between the <title> and </title> elements.  This is shown at the very top of the browser as well as the click able text in the search results.

Here are the most important points when it comes to writing awesome title tags that will give you the best rankings and click through rate.

1. Limit Title Lengths to 65 Characters
   Why 65 characters? Because that is what Google’s limit is. If your title tags are longer, the rest of your title will be cut off and replaced with a “…”. This isn’t a hard and fast rule, and other search engines have experimented with longer text. Just make sure everything that is important is in that first 65 characters.
2. Use Targeted Keyword Phrases
   The bulk of your titles should consist of 2-3 keyword phrases.  Generally, these terms should be in the first and second positions of the title.  If you can, use longer keyword phrases instead of shorter phrases, as you will have a higher click through rate.  For example, instead of having “Potted Plants | Potted Trees | Ashby’s Green Supply,” try using “Potted Plants and Trees | Ashby’s Green Supply,”  This looks more natural as well as optimizes your website for two phrases while cutting down on characters.  An important point to mention is this only works when your page is relevant to both phrases.
3. Branding Your Website
   Using your website’s name is extremely important in the title.  Not only will you rank well for your website name (which is always a good thing) but you will build authority for your website with the search engines as well as with visitors.  It is also likely that your website name will include important keywords which is an extra plus.  Add your website name to either the front or the back of the title.  I prefer the back, which gives more importance to the keywords in the front.  Once your site becomes more popular, you might want to change this.
4. Use a Separator
   When you are separating your keywords and website name in your titles, always use some sort of separating character.  Many websites use the “|” symbol (sometimes known as the bar, or pipe).  I have also seen hyphens “-”, arrows “>” or commas “,”. You could actually combine them in certain circumstances.
5. Target the User
   When creating title tags, put yourself in the shoes of the user.  If you were to search for a given phrase, what text would you click on?  If your website is informational, use more descriptive titles based on the information you have.  If your website is for users to do some sort of action (purchase, download, leave information), make sure the title reflects that this can be done on your site.
6. Repeat Titles on Website
   An important strategy for title tags is actually using the titles on the website.  If my title is “Buy Potted Plants | Ashby’s Green Supply,” then use the term “Buy Potted Plants as the headline of that website.  Do this preferably in the H1 header tag.  This isn’t only valuable for keyword density for the SERPs, but also will improve conversion rate for those users who have clicked through.
7. Keep Consistency Throughout Your Website
   Once you have decided on a method, stick to it.  There is nothing worse then having different title tag methods for each page on your site and having the search engines confused.  Users will also become familiar with your title tag structure, in that your page will be easily recognizable when they see your website in the search results.

This is a pretty good list, but is there any suggestions that could be added?