In short, I create hypothetical products and put them in a real world setting. I work the product out on paper in the form of mock full-color ads. For most of us, advertising is the key twentieth century communication that we react to. The writing of ads forces you too look at your product from a marketing standpoint. How you sell the ultimate consumer can be just as important as what you sell.
Consumers are neither rational or consistent in their purchase habits.
If you can't sell the product or service with an ad that focuses on a single selling proposition, the chances are you won't be able to sell it at all. When you sell your product, you're going to have to communicate your product to someone. Because paper is a hell of lot cheaper than prototypes. Ads allow you to experiment on paper every step of the way and validate every part of your product before you physically make it. They will help you find fatal flaws faster.