This research aims to go beyond classical brainstorming methods, with the classical divide between (irenic) idea generation and (eristic) selection, to explore creative means for shaping group creativity by intervening on the socio-affective dimension of group dynamics. In this paper, we develop the design rationale of a suite of four group creativity workshops (Time Trial, Idea Sports, Argument Clinic and Idea Gym), based on three approaches to introducing creative tensions, defined as pressure and disturbances in time management, in interpersonal relations and in use of artefacts in the workshops. We also report on a preliminary evaluation carried out with groups of students, into Masters-level training.