Originating from product life cycle management, more and more Digital Twins (DTs) are implemented in research contexts and industrial use cases. DTs allow for continuous information provision, a mandatory requirement, e.g., for the circular economy. Implementing a DT faces integration challenges and requires precise planning for selecting specific components of a DT and its functionalities. A process model supports making informed decisions, structuring the application and its demand for certain DT elements, and streamlining implementation processes. Albeit specific implementations come with individual requirements, a generic process model allows for the transfer of general instructions and rules to particular cases. Our ongoing research focuses on developing a process model for implementing DTs. The process model builds upon the VDI norm 2206 for implementing cyber-physical systems and enhances the VDI norm by providing more granular sub-modules. This paper reports on the first development steps and preliminary artifacts, e.g., a visual inquiry tool in a DT implementation canvas. Our research builds upon a thorough analysis of theoretical and practical requirements and existing frameworks and architectures for DTs.