How to Brainstorm
Meet away from usual workplace (different building, hut in the mountains).
Use plenty of paper. Cover the walls with it!
Draw. Scribble. Use lots of coloured pens.
Three rules during brainstorming:
1. No one is allowed to criticise another's ideas.
2. Engineers must not say it can't be implemented.
3. Graphic designer must not laugh at engineers' drawings.
Only after brainstorming, organise ideas and consider their practicality and viability.