I need help. Seems like it should be a simple task but for the life of me I can't figure it out and I think I'm about to lose my mind.

Specifically, the tutorial for "fantasy realms" where it discusses how to draw a mountain, but I think it really should apply to tracing anything like a shoreline or a what have you. The instructions in CA26 Mapping Guide-Fantasy Realms state:
Start by selecting Mountain Spine. Draw the main ridge for your
mountain group. Next select the Mountain Base drawing tool. Draw
the footprint of your mountain group. Note that edge of the base
touches each end of the spine path. The width of the mountains is
not a calculation. Simply, it is as wide as you want to suit your map.

Next, we’ll draw the shading. Select the Mountain
drawing tool. Start at one end of your mountain
spine. Click to start the tool then use the tool’s Trace
function to trace the spine and then trace the outer edge of
the base. Looking at the diagram of our example, we'd start
the drawing tool at A, select B to trace, then start the trace
at A and end the trace at C. We’d then start a new trace at
C, select D to trace, trace the edge of the base along D and
end the trace and the tool at A. This will shade our
mountain group.
So I draw the spine. The I draw the footprint. Now I want to trace the spine and one half of the footprint for the purposes of shading. So I select the "mountain shading" tool, then select the "endpoint" button and click on the end of the spine. This attaches a line to to the end of the spine. Next I want to click further down the spine so my line traces it and then continue to it's other endpoint and the around the outside of one side of the footprint and finishing off back where I started. Problem is it doesn't trace anything and only makes a big ugly fractal line and eventual polygon that isn't a trace. Seems to me there should be a sort of "magic wand" effect where the line hugs the existing line...

I see in the Command box the instructions:
Next point: (DEL - back, Space - Randomize, L/R Arrows - Depth, U/D Arrows - Strength, T - Trace):
but have now idea how to utilize it.

Thanks in advance for any assistance.