In the context of smart cities, co-creation is being used as a strategy to engage citizens and stakeholders in various scenarios such as identifying needs and problems, as well as developing and validating new intelligent products and services for a city. For the development of this strategy, different tools have been proposed to facilitate interaction and collaboration among participants, looking for to achieve the established goals according to the defined needs. However, despite its extensive use, there is a need to develop systematic processes that enable the appropriate application of the strategy to ensure high-quality results. This article aims to address this issue by describing a method that can guide the planning and execution of co-creation activities for the development of smart products or services. The method consists of five stages: planning, presentation, development, closure, and analysis. Each stage proposes a series of activities aimed at successfully conducting the co-creation sessions and producing results that contribute to the design and development of new intelligent products or ICT services.