Every talk, regardless of whether the speaker realizes it or not, has one of four major goals.

1. To persuade or get action.
2. To inform.
3. To impress and convince.
4. To entertain.

Magic formula:
Start your talk by giving us the details of your Example, an incident that graphically illustrates the main idea you wish to get across.
In specific clear-cut terms give your Point, tell exactly what you want your audience to do.
Give your Reason, that is, highlight the advantage or benefit to be gained by the listener when he does what you ask him to do.