A low power laser works well too. I have a 2500mw el cheapo that will cut thru typical veneers fairly easily (.020-.030). Made a small vacuum table that works with the DC nicely.
Cutting veneers with a drag knife can be testy at times as others have mentioned. Another issue is that the knife can flip the small pieces around and they can end up in the wrong place at the wrong time. A vac table can be problematic if the holes are not real small.
I posted some examples a while back at:http://forum.vectric.com/viewtopic.php?f=27&t=29430&p=212291&hilit=+marquetry#p212291
The pics are the very first attempt, since then I have improved it a lot.
"If you see a good fight, get in it." Dr. Vernon Jones