Tell people why they're invited and what you need from them. Some participants need prep time, others work better on the spot. Give both space to contribute and the workshop magic happens.
Chapters
Recently I was asked, how do we get participants to do the best possible work and get excited about the workshop? The short answer is, make sure that they know why they're there and why they're invited. Everyone who feels like part of the bigger picture and knows exactly what they're bringing to the table will obviously be at their best selves. Also make sure that you give them room to contribute and be aware that there are different personality types. So maybe someone needs a little bit of time in advance to actually think what they want to bring into the session, and others are just speak-to-thinkers and enjoy to think on their feet. So provide introduction and enough space for all these different personalities, and then let the magic happen.