Freely printed from: https://learn.nimja.com/basics/explaining_hypnosis
Before you begin with trance, it's very helpful to explain/demistify hypnosis. A lot of people have preconceptions and ideas into how it works, mostly from TV, which can differ wildly from your own experience.
In working with inexperienced subjects it is important to take away the misconceptions that people have, related to hypnosis.
A good way is to ask a simple question:
What is your experience with hypnosis?
This will almost inevitably start a discussion about what they know (and don't know), which allows you update their knowledge. While doing so, it's important to focus on positives.
Besides the basics on What Is Hypnosis?, work on your own examples or learn from others in how to explain it.
A few examples:
You know that feeling when you get completely lost in a book or movie? That's trance.
Do you ever get lost in that feeling of doing something, like drawing or programming? A lot of people call that flow-state, but that's just another word for trance.
Hypnosis is no more than a guided trance.
Do you meditate? Did you know that it's a form of self-hypnosis?