The following is an excerpt from the CoachStart Manual.

Creating Your Speech

You need to decide who you will speak to.  Who do you want to help? Women?  Teens?  Corporations?  People in Rehabilitation?  Spiritual people?  When you know who you will speak to/help, you can start to try and find them.

Ideally, choose people who would pay for your services — who have money. Pick a topic which solves a problem people have. If you speak on ‘enlightenment for underprivileged children’ you’ll likely command a lower fee than if you speak on ‘how to make your customers choose your company over others’. Of course — if money isn’t important to you, this won’t matter.

Speak on something that’s VERY important to you and which you feel makes a difference to the world.  If you don’t come from the heart and say what you really feel/mean, you won’t get the gigs, you’ll be unhappy, or both.