Worked on my ruined tower small bits at a time. The snow is a mix of PVA glue, white paint, baking soda and a small amount of glitter. The glitter didn't come through much to give the effect of ice crystals. I'll try another layer of just glitter and PVA glue to see if it reflects the light better.
I've got one ladder built and painted. I still need to get a second ladder built and painted. I'm also working on a rubble pile to represent the section of the ruined tower that is on the ground.