The first is called Instant Snow.You can purchase it here if interested.
The second experiment was perfect since we were learning about the states and changes of matter in science.
Fill balloons with water- small, medium, and large- and place in bowls with the tied side down so it will create a flat surface. Lay something on top of the balloons to create a flat surface on the top as well. Once frozen, remove balloon and stack balls using salt to help them adhere to each other. Cut out decorations with felt and stick to ice.
To help my students understand Winter we do a lot of crafts about snow, snowmen, snowflakes, and we talk about how to stay warm when it's cold outside. Here are some of our projects:

We made snowmen out of our names...

First, the snow falls. Next, it grows. Last, it is finished. |
First, it snowed. Next, they made snowballs. Last, they decorated it. |
This was a center they completed on their own. I provided all the pieces and they created their own snowmen.
You can go check out this website Make-a-Flake to create online snowflakes from paper. After practicing on the website students can go create and cut out their own snowflakes from paper. I hung our up on our class tree.
Of course I also take this time to talk about animals that live in cold habitats like penguins. We read a lot of books about penguins. Then the students do a step-by-step drawing of a penguin and write some facts about it. To help them with this we completed a tree map.