Re: roller plotter or parallel rulers?
I use two triangles but my fav tool is simply a see through protractor that is big. One can line it up with north and measure angles fairly well. Measure the bearing to your "aid to nav" and then put that angle on the icon on your chart. You are then along a line passing thru the center of the protractor (after correcting for local variation). Do it again for a 2nd aid and the intersection is your position. My fav compass is a simple Silva compass with a fold-up mirror. It is light, easy to use and for me, intuitive.
A large right triangle of clear plastic is truly valueable to go from Lat and Lon alomng the chart sides to your place on the chart.