1. Give each person a large sheet of paper. Ask them to fold their piece of paper so that it is divided into four equal sections.
2. With the paper in portrait, ask the group to write the name of their idea and the problem it solves at the top.
3. Give them 5 minutes to draw their idea in the top left box with enough detail that someone can understand it without explanation.
4. Afterwards, instruct everyone to pass their paper to the person on their left.
5. The next person should look at the previous idea and develop it further, drawing their version in the next section of the paper.
Tip: A variation of this tactic is to ask each person to additionally include a statement about why the previous idea would fail.
6. Carry on doing this until all the sections of the paper are full.