[Matra et Alpine]

OK, so that one was a little harder.

You had to follow the crossing instructions VERY clearly and each step and EVERY step.
Miss one and you'll struggle.

To try to assist, what I've done is marked up the map in my typical intermediate stage.
This is as I go through the grid lines and I mark where the road crosses the line number given. THEN I draw the route - and remove the cross lines.

So the first map is just my 'working'
The second map is the route as I then read it to the driver.
NOTE: Here you see where I will use the route line and swap it from one side of the road to the other.
This becomes important when 2 junctions are near to each other. It's important that as a nav your drawings cannot be mis-read. So by putting the corner mark on the OUTSIDE of the corner I ensure I don't get confused at the point where they are close .

Going back to the skills, for grid lines you want to tick each number on the instructions as you mark it on the map and then look for the next grid line number in the instructions and find where it is on the road and then mark it and tick the instructino and continue till all are done.

Anyone still struggling with this raise it in Q&A and we'll try to work out a better description.