The crazy eight is another ideation technique that uses time constraints to force creativity. But this time at a crazy level.

You'll give to everybody 8 sticky notes, or a sheet of paper that they fold in 8 parts. The facilitator then explains that everyone has 8 minutes to sketch quickly with a title 8 ideas. Every minute the facilitator let's the team know at which idea we are.

You can decide that you end the ideation exercice here and maybe people will share and regroup similar ideas.

Others who use the crazy 8 technique, then ask participants to create a more detailed sketch of the most promising idea of the 8 in a long period of time. For example 20 minutes. 
After that participants will then share the developed idea.