You’re absolutely doing it wrong. Just kidding… I don’t think there’s a right or wrong way to do “it”.
Doing it, is the key phrase here. You’re basically “sketching” in three dimensions. If you were trying to lead a group of folks toward a common solution, it might prove a bit more difficult doing it this way; more ground might be covered if your thoughts could be captured and transmitted to others.
The advantage to sketching/drawing is that it’s basically available anytime, anywhere.