Blanket of Snow Tree: I've done this to my trees for years and it is a lot of work but so worth it--- To create a convincing effect of thick snow, lay lengths of rolled cotton along the branches of your tree. Then sprinkle crystal snow over the cotton.
Ice Balloon Lanterns: Fill balloons with water then freeze. When they're about frozen, snip the top of the balloon and peel away. Drain any excess water. It's important that one side of the balloon remains unfrozen/open, so you can place a candle inside.