find a good close up picture of your dogs face like this
open it in photo shop
go to menu Image - Mode - Gray Scale
then go to Image - adjustments - Brightness and contrast
Change the contrast to plus 99 and bring the brightness down to -30 or so
you can play with these values depending on your picture and what you think you can carve in detail.
and you should get something like this
were carving pumpkins tommorow I will post some pics of our pumpkins, oh and I use a dremel to carve pumpkins, it's awsome to sue to carve