I think I'd use extra hikes as motivation. Here is an exercise that can be fun. First a person needs to know their pace on trails. Mine is about 3.2 mph when moving. A stopwatch would be helpful to start and stop for any breaks.

Rather than putting tick marks on the trail with distance, time is easier. The number of tickmarks is the time to walk the trail in minutes plus one for the start. (Run the watch for a minute before starting or the times will be off.)

Then simply walk the trail and stop every 10 minutes, stop and use a GPS to save the position for later reference. This will teach that time can give a very good indication of position.

On the way back, use topographical features to refine the position.

After getting home, compare where you were based only on time with where you actually were.

The map is made with Topo Explorer. It saves a lot of busy work in making the tick marks.