Like MacGyver, designers are problem solvers who have to find elegant solutions. The design problems are the short time and the small budget, limited by customers. To solve problems, designers have documents, processing, and knowledge. They actually have two potential solutions: efficiency and, most important, expertise. User research is a tool designers can use for efficiency. In that way, they can reduce the number of participants, so that the user has fewer interlocutors, increase recruiting efficiency and research only what is necessary. Another idea is simply to ask customers how they found the products, what M. Jackson Wilkinson from Viget Labs calls “guerrilla design research.” He also insists on talking to people who talk to customers, to tell you what they hear about, and use the customer feedback loop. Interaction design is another tool for efficiency, which includes starting delivering sketches, testing using paper prototypes, always exploring alternate designs and working within agile processes.
For expertise, designers have to solve and design challenges by “design thinking.” The shorter way to go from the point A, the problem, to the point B, the solution, is design patterns. That means using solutions many others have for a particular problem in past. But it is not necessarily the right solution to your problem. So, you have to think about design principals, like cognitive load (think simple) or loss aversion (think positive). If it is not adapted to your problem, design theory will help you to change the way you see things. And if it doesn’t work, you still have the trial and error method.