Brainwriting
Speaking up aloud in a room full of people is not everyone’s cup of tea. But that doesn’t mean they don’t have anything worth saying. Encourage ideas from everyone in the room with brainwriting, a non-verbal exercise that promotes individual thinking and collaboration through writing.
The most common format of brainwriting is the 6-3-5 format. Here, 6 people write down 3 ideas each within 5 minutes on a piece of paper. Next, everyone swaps their papers, reads what's on them, and then adds 3 more ideas. These can be new ideas or ones that build on existing ideas. This goes on for a good 6 rounds, after which all sheets of paper are collected and the ideas on them discussed.
Feel free to play around with the number of people, ideas, and rounds in this exercise according to your workshop needs.[1]