GFPT just to add what Edition12 said. Further to a cellosheen WAC, cover your current VNC in matt clear contact. Over the period of a few months and a few navs it is going to cop a beating. Chinagraph pencils in a couple of colours and sooo easy to wipe off and edit.
That first time a turn point comes up on your nose, on track and on time to the minute with a 20kt crosswind is just pure gold
And from my personal stash of PPRUNE GOLD-
How to Navigate Visually