This deserves a special page. Webmaster tools if the first tool we use when a client complains of low traffic. Webmaster tools is provided by Google, giving feedback on what is right and wrong with your site from Googles perspective. I found this great video that explains it better than I can.
What keywords though? Although difficult, if you’re serious about getting better rankings, don’t ever write any new blog article without first considering the effect it will have on your search ranking. Think about the topic and keyword focus before you start. Here’s an intro video worth watching that explains it well…