I've found it amusing that as the aircraft flown have got bigger the kneeboard space required has got smaller.
I started off with an A4 sized one when learning to fly (Tomahawk). Reduced that to an A5 one when I started producing my own PLOG's which were also the same size as approach plates - made sense (Warrior).
Now - line get's drawn on map, route get's programmed into GNS430 or KLN90, Plates sit in trip folder ready to go on control column clip. All the writing is done on a 'post-it' - one per trip which is great for doing logbook and techlogs afterwards (Aztec/Citation).