Write the topic in the center of a blank sheet of paper. Draw a circle around this starting point. You may want to write this original point in a larger text than you will use for the rest of the mind map.
Draw lines extending outward from the center circle and write subheadings, categories or topics related to the main topic on each of these lines.
Draw further lines extending from these topics for additional details and points related to each.
Continue to draw branching lines from each subsequent point on the mind map, working outward as you explore the topic at hand. The map can be as large as you need it to be to thoroughly explore the topic.
Start a new mind map if you run out of room. Begin again with one of the subsequent topic points as the new center point, and keep branching out from there.