This research reports on the improvement of engagement activities with academics and public sector organisations in the northwest of the UK. Such activities are often supported by tools and resources public sector professionals use in their creative engagement practice. However, generic and prescribed tools do not ensure an appropriate engagement with the communities they work with. There is a need to tailor such tools for specific contexts to accommodate multiple design languages and skills of those involved in engagement processes in order to support them in design and decision-making processes. This paper presents a new design practice, where engagement practitioners develop their everyday activities through co-designing improvements of tools, enabling advocacy on the act of improvement. In this practice, engagement practitioners look at the instructions, functions, and flexibility of tools they use, provide suggestions for improvements, and make design decisions that enable better creative engagement activities through a series of co-design workshops. This research follows a Participatory Action Research (PAR) approach, where four case studies document the co-design process, and the planning and delivery of improvement workshops. The paper discusses the insights and lessons learned from the co-design process and the impact of the new improvement practice. The outcomes of this research include building design capabilities for improvement in participants, insights on the improvement of tools, and guidelines to conduct the design practice. This research contributes to the shift in design agency from ‘transferring improvements to’ to ‘co-designing improvements with’ individuals and organisations.