Begin with a circle. Write your idea (problem, issue, goal) in the circle.
Now write every related thought or idea around the circle, like moons orbiting a planet.
Don't edit yourself. Jot down your ideas as fast as they come, in any order.
By laying out your ideas like this, you can often see common elements or links between concepts that you wouldn't see if you had written down your ideas in a linear, list-like way.
The mind map is a good place to begin. Your ideas are all in front of you. As with any map, you first need to know where you are.