This is a research and design graduation project for the Master-education tracks Integrated Product Design and Science Communication TU Delft, with a Sustainability-annotation (TiSD). The client of this project is Euro RSCG Bikker, a consultancy with the proposition ‘committed to trust’. The Bikker-consultants develop products and services in the form of advice for corporate communication professionals of large organizations. Since current investigations and publications related to ‘trust’ are hardly comparable or applicable for strategic corporate communication professionals, Euro RSCG Bikker was looking for generic, supportive tools, methods and techniques to make trust and hence the agency’s proposition more tangible in their advice development process. Eventually, Bikker wants to develop a ‘trust measurement instrument’. To anticipate to the desire of Euro RSCG Bikker for tools, methods and techniques, a research and design process was initiated. The process aimed to develop a Toolbox and ‘trust determinants’ for advice development of Bikker consultants. The underlying research question was: “What theory-based trust determinants are potentially useful for corporate communication consultancy practice according to Bikker consultants?” To answer this question the author conducted a design based research to develop a toolbox with trust determinants for the analysis phase of advice development of Bikker consultants, in which consultants analyze the client's organization, identify problems, and set objectives for the advice that needs to be developed. Various research and design techniques were used to investigate trust, corporate communication and consultancy practice at Euro RSCG Bikker, and to develop the toolbox and its trust determinants. The preliminary design proposals were tested by practitioners and optimized by the author, but Euro RSCG Bikker will take responsibility for the further development of the toolbox. The final set of trust determinants is Common values, Consistent, Transparent, Innovative, Freedom, Shared success, Stakeholder involvement, Stakeholder relationships, Pride, and Respectful. These determinants could be identified in theory ánd practice as indicators of whether and why there is high trust, ánd as strategies to build, restore, or retain trust íf that appears to be low. The toolbox contains an underlayment, coasters for each trust determinant, pawns, and paper money. A client can also introduce a new determinant (‘Jester’) in order to encounter client specific desires and whishes in the advice that a Bikker consultant is about to develop based on the analysis of the organization. In a playful interaction, both the consultants ánd clients can do a ‘trust-diagnosis’ of the client’s organizations, and ‘set starting points for the advice’, which forms a fruitful base for a mutually rewarding consultant-client relationship. The research conclusion is a list of conditions for theory-based trust determinants with potential usefulness for advice development practice at Euro RSCG Bikker in general, based on the toolbox design results. The trust determinants require further elaboration in the future, but for the current consultancy practice at Euro RSCG Bikker they form a start. Also, the toolbox requires maintenance and an update in the near future, especially if Euro RSCG Bikker wants to develop a trust-measurement instrument eventually. The report ends with various recommendations for future research into trust, design-based researchers, and future exploration opportunities for Euro RSCG Bikker to extend the proposition ‘committed to trust’.