Made a planet prop for the Space game. It's ~4 cm in diameter. I have a lot of cotton wool lying around, and wanted to know if it's good for doing clouds. It is!
The full recipe for this one is:
1 Paper ball (I guess any ball will do, but the slight texture of the paper pulp is so damn good).
5 colors, blue, green, two browns and white for ice, showing just barely on top of the planet.
Cotton wool (from the cosmetics section).
PVA glue that dries clear.
2 Sticks (toothpicks or some spare plastic bits).
1. Paint the ball. I didn't really mix any colors here, but tried to carefully blend with just flat colors.
2. Make a mixture of 1/4 of glue and 3/4 water.
3. Pluck tiny bits of wool and throw them in to the mix. With this scale I found that the size of my thumb nail are good, just try to get them as "airy" as possible.
4. Take your sticks and fish the wool from the glue, drain it off some against the border.
5. Slap the wet wool in the planet and stretch it in shape with the sticks. Try to stretch it so that there's no big clumps. You might want to get some tissues here to wipe the watered glue that'll start running around the surface.
6. Bear in mind that the PVA glue dries clear, so don't thin out the wool too much. I found out that if the clouds look good when wet, they are barely visible when dry.