I bought a quarter mil chart once but found it a faff to use in practice. Too much info, and you get to the fold too quickly. My wife liked to look at it whilst I flew from the half mil. I assume that helicopters operating at lower levels would find the quarter mils useful.
I use the fine point overhead projector pens (wih my track line, notes, and a large wind arrow, all in green or blue). Chinagraphs rub off and a chinagraph track line is over a nautical mile wide. I used to stick on compass roses for diversions, but nowadays use the small rose around a VOR on the map to give me quick tracks for diversions.
On French charts I have used a pencil, which is not ideal as the track line is a bit hard to see at a glance. Next time I go I must invest in a high-tech coloured pencil.