Play some loud cheering and do your thing. Then have some friends or family members come and cheer and clap LOUD
We have the chance to have 'demonstrations', where we have people looking at us while we work, but it's not a show.
First, we don't work young horses, we just show them the audience. We ask the crowd to help us to get the horse used to applauses, by explaining them that it's a young horse.
We do it again as long as it is needed, we take our time, by rewarding a lot. Horses need to trust themselves, and us, to know that we will never put them in danger. Finally, they will associate applause to reward.