More parts
Not the best way, but an old trick was to Xerox copy the parts shown on a plan. Roughly cut them out and place them on the balsa sheets. Using a hot dry iron, rub the image in. Upon removal of the paper all the black lines will show up, enableing you to cut out the part.
I now go the laser cutting route, unless I need just one part.
Just one thought.
Wm.