Use Only Quality Meta tags
When adding description and keyword meta tags to each of your pages be sure to include only quality words that are actually listed somewhere on the page. If not, it might be looking a bit spammy and your pages might get the dreaded "supplemental result" label.
For example, this page's meta tags might look something like this:
<meta name="keywords" content="meta, tags, quality, keyword, description, page" />
<meta name="description" content="Learn how to use meta tags more efficiently" />
The longer the body of your post is, the more descriptive your description can be, although... it seems that keeping the keywords at 10 maximum might be a good idea, so don't go overboard.