I battle smooth butter cream, how would you add these perfect snow mountains, then trees on top of perfection like this?
just looks like decent piping work and possibly a little work with a palette knife.
I rather agree w/leah. Maybe used a stencil for the mtns, then piped the trees. The trees look like just dots or maybe a leaf tip (like 352) held straight up & down and light pressure .....well anyway, that's what I would do :)