Always blip the revs when changing down, keep around the 1800-2000 rpm mark when in each gear driving a TDI.(except when in top gear and I want to get to 70 when its 2.500). I also drive to the conditions and were possible miss gears out, less strain on parts and a more comfortable drive, along with what I would consider large fuel savings I have driven this way now for some time now and it still amazes me how much fuel I save by driving this way.