Despite the large number of available creativity techniques such as Brainstorming and Six Thinking Hats and their widespread use in idea generation workshops, it remains unclear what specific aspects creativity technique users perceive as helpful. We conducted five large-scale product development workshops with 216 inexperienced students in groups of four to six people and personally interviewed a subset of 87 participants using the repertory grid procedure. The results reveal a framework of facilitating and impeding factors users associate with the methodological frame, the process view and anticipated idea characteristics of creativity techniques. Particularly helpful and differentiating factors cover visual, cognitive and emotional processing systems. In addition, we evaluate 11 commonly used creativity techniques and present underlying reasons for why some of them are perceived as more helpful than others by inexperienced users. The results thus provide a stepping stone to understand the users' perspective on creativity techniques, improve existing techniques and develop better versions of them.