Draw your map on a piece of paper. Think about your chosen location. What does it look like? Is it mountainous? Is it a desert? Does it have both of these features? Or others? Make sure to include plenty of challenging terrain in your map. You do not want your hero to find the treasure too easily. Pick a good spot for the treasure. The treasure should be located in a remote, difficult-to-access spot, so that it will be very tough for the hero to reach it. Use pens, markers or pencils to sketch the map.
Plot your story. Figure out when to introduce the map and how the characters will use it. The treasure map should be an important fixture. It will be a major prop in the story, so put the map into play at a dramatic point in the story to increase its effect. Continue to reference the map throughout the story.
Include a copy of the map in your story. Scan the map into your computer, and print it out. Place the map in the book at appropriate intervals, such as times in the story when the characters make use of it. Help the readers track the characters' progress by including dotted lines on the map to show how far they have gone.