For me, this is the most time consuming part of drawing a map. Using computer software, I can create the roads and route of the actual course in about 15-30 minutes. It might take twice that long to create an inset diagram of the start, finish and turnaround. This is due to the fact that these locations are specific and unique; even reusing and modifying diagrams from previous maps can take time.
I wonder what constitutes an adequate description of such points. For example, if a text description is specific enough - "20 feet 3 inches north of storm drain, 7 feet south of fire hydrant, directly opposite post office entrance drive" would that suffice in lieu of a diagram?