I usually use a series of exercises to break it down for people.
Usually start by having a research read out so everyone starts from a similar baseline. Then break into teams of 3 (just the right size, no one can not participate in a team of 3) and launch into 45 minute exercises. At the end of each 45 minute work session there is a 15 minute read out where each team presents their concepts to the group, then the groups switch trade concepts and build/refine off of those.
For example, the first exercise might be to write problem statements, or use cases. Teams trade problem statements then the second might be to think of a solution for the problem statement (I’ll usually throw in a twist for each team, like solution must include or not include x technology). Third exercise might be to list the problems with the concepts you have been handed. Fourth to solve those problems… and so on. Then I usually will end the session with a forced rank of some kind, or mapping the concepts on a 2x2.
Usually I have one designer on each team to sketch concepts as they go. Also this takes 2 days.