Any Google AdWords campaign is a continuous improvement process to constantly improve the ROI. First, create a conversion tracking plan to track conversions from the beginning of your campaign. Next, use Google Analytics to determine the traffic sources that are delivering quality leads. Then, update the ads, keywords and ad groups in your campaign to maximize conversion potential. Utilize Google AdWords reports to understand where you are getting conversions from and what is converting at a high rate. Finally, always keep an eye on your competitors to see what kind of campaigns they are running and how you can improve upon them.