Use your head when selecting keywords. First of all be sure the keywords you use in your titles, headlines and meta tags are actually used throughout your pages and are relevant to the subject. But stop and think a moment - lots of people tell you to carefully add meta tag keywords. But that s not necessarily good advice. You should add the things you think people are likely to type in a search engine or directory search window when trying to find mmsystem006 information or whatever your page is about.
Studies show people use search phrases much more often than they search individual words.
This is useless. If I type in Panasonic CD-ROM drivers I am much more likely to get a meaningful return. Most people have learned this and use search phrases. So my page on this subject uses that keyword phrase in the meta tags and elsewhere. Many Web developers are not aware of this and still use single search words in their meta tags and elsewhere.