I have invented a visualization game involving clouds which I find very interesting. It entails looking at certain cloud formations and seeing them as the surface of another world. To do it there needs to be a combination of high and low clouds and blue sky in the same area. The clouds that are higher in the sky are focused on and are seen as the surface of the alien world, the closer (brighter) clouds are seen as clouds floating over that world and the blue skies are seen as shadows or forests on that world.
This process gives the impression of viewing a planet from a few kilometers above it and at an angle. The shapes on sees are very interesting and invoke different landscapes and terrains. I do this lying on my back, of course and the key is to focus the eye on the most distant, higher clouds that represent the planets surface. Higher clouds and lower clouds will move in different directions and so it will appear the lower, brighter clouds are clouds moving over the surface of the alien world which is represented by the higher, less bright clouds which are still brighter than the gaps of blue sky which appear dark in comparison with the clouds and can be seen as shadows on the alien world created by sunlight or by the existence of forests.