Collaborative Chance Discovery aims at determining a rare event as a chance for future decision making from a set of potential chances that have been identified by computational methods. Typically the members of a workgroup, which are concerned wit h this task, will imagine scenarios that describe situations and event sequences during which a chance could be used. As the process benefits from an increase in trust between the group members, it raises the question how such an increase can best be achieved. Based on previous experimental research, this paper proposes a set of strategies that are expected to increase trust within work groups. It is argued that goals, plans, and actions related trust enhancement have a symbolic and an instrumental meaning. The fact that also symbolic meanings of trust are communicated, lead to a symbolic communication model of trust that may have particular relevance for scenario emergence. The identified strategies are currently used in group experiments, but they also will be useful for the management of workgroups concerned with scenario emergence.