We are convinced creativity is a muscle. You need to train and keep it active to function at its best. Like a muscle, you need to stretch it before using it. That's something we forget at workshops and ideation sessions. We tend to introduce the agenda, explain the challenge, and jump immediately to action.
It's difficult for people to go from 0 to 10 in no time. That's why we recommend you to prepare some warming exercise before you get everyone to work, especially if you are running a workshop with clients. With these simple tricks, you'll make sure you break the ice and have your team's brain ready to ideate.
It's not about starting a beef with your team/audience. We learned this when we collaborated in some workshops with our friends at IAM. The goal is to provoke everyone's shared beliefs with a short presentation that includes exciting case studies, gifs, quotes and images. Make it as random as you wish. It has to be inspiring, concise and straightforward. At the end of the capsule, you want to leave people feeling like "wow, yes! I also want to change the world like these awesome ideas!".
When energy is low, or participants don't know each other, you might want to decide for an ice-breaker. There are tones of them. The importance is to choose the right one that will help you get people moving, laughing and feeling ready to work. If the audience is formal and not used to creative exercises, we recommend you go for something safe and short. Otherwise, go crazy and have fun. You can get some inspiration here (select "energisers").
Another way of creating the right vibe is to set everyone in small teams and give them a topic to discuss. This issue could be work-related. For example: "Let's discuss the challenges of the project". Let the small teams talk first internally, and then share and discuss with the whole group. Moderate the conversation to make it rich and exciting.