Tangible and physical user interfaces have shown much promise in the HCI literature, yet there is a lack of examples of successful deployment in real-world situations. Compared to graphical user interfaces, physical interfaces are more expensive to design, build, implement and deploy. Nevertheless, in some use cases, a physical interface is more effective and intuitive than a screen-based alternative. We developed Conjoint Control, a practical approach that can be applied by interaction designers, including those without a specific technical skill set. It consists of a set of guidelines for collaboratively designing, building, implementing, and deploying bespoke physical interactive devices for well-defined use cases. We applied the approach in a real-world use case, creating a physical interface for an office setting. The approach produced an interface that was positively received and well used, but also dependent on sustained maintenance. Overall, we found that with Conjoint Control it is possible to create bespoke physical user interfaces and deploy them successfully in a real-world setting.