Many people incorrectly believe that good meta tags are all that is needed to achieve good listings in the search engines, which is entirely incorrect.
In the early days of the web people were able to get great listings from optimizing just their meta tags, but the increasing competition for good search engine listings eventually led to many people spamming the search engines with keyword stuffed meta tags. The result is that the engines have changed what they look at when they rank a web page.

The search engines now usually look at a combination of all the best search engine tips to determine your listings, not just your metas - some don't even look at them at all! What this means is that your page should have a combination of all our tips implemented on your page - not just meta tags.

What they look like

• Description Meta:
  <Meta NAME="description" content="This would be your description of what is on your page. Your most important keyword phrases should appear in this description.">
  
• Keywords Meta:
  <Meta NAME="keywords" content="keywords phrase 1, keyword phrase 2, keyword phrase 3, etc.">

Tag limits

• We recommend that your Keywords Meta not exceed 1024 characters including spaces.
  
• We recommend that your Description Meta tag not exceed 250 characters including spaces.

Meta description tips

• Include 3-4 of your most important keyword phrases. Especially those used in your title tag and page copy.
  
• Make sure you accurately describe the content of your page while trying to entice visitors to click on your listing.

Meta keywords tips

• Watch out for repeats! You want to include your most important phrases, but when doing so it can be difficult not to repeat one word many times. For example, "caribbean vacation" and "caribbean vacations" are two different phrases, but the word "caribbean" appears twice. This is okay to do in order to make sure you get the phrases you need in there, but becareful not to repeat any one word excessively. There in no actual limit, but we recommend that no one word be repeated in the keyword meta more than 6 times.
  
• Don't forget plurals. For example, a travel site might have both "caribbean vacation" and "caribbean vacations" in their keyword meta tag to make sure they show up in both searches.
  
• If you know of a common misspelling of a popular keyword that could be used to find your site you should enter it in your keywords meta tag. For example, a travel site might use "caribean " in their keyword meta since it is a common misspelling for "caribbean".