(This is good to do with a concentrated mind, especially after open awareness practice. It couples well with Insight work into the nature of impermanence and not-self)
We spend the vast majority of our life in the horizontal world. Humanity has made that world to suit its purposes–our cities, roads, screens, and interactions all take place here–and when we live in this world we feel an inflated sense of importance because of that. We are big important humans doing big important human things. However, when we look up into the stars, we feel tiny and insignificant. This is a wonderful things, because that is reality. We are teeny tiny little bags of meat living on a planet that is far bigger than we can hold in comprehension; the Earth is itself minuscule next to the size of the Sun; the Sun being only the tiniest grain of sand in the beach that is the galaxy, which is one of a truly mind-boggling number of galaxies in the universe.
Not only is this perspective shift helpful in that it gives you a more accurate view of reality, it is also really helpful in contemplating impermanence and not-self. The shifting of perspective casts a new light onto the importance you attach to various things. The importance you attach to, for example, your mother, or your car, doesn’t really diminish, but you do realize that the meaning that you put on that is entirely self-created. The universe certainly does not put that meaning there. In fact, the universe is going to do what it is going to do, regardless of your feelings on the matter. In this way, losing those things becomes easier to accept. This vast, impersonal universe that you are only the tiniest part of doesn’t put any weight at all onto the fact that your father will die, or the fact that you are growing old. You do, but the perspective shift allows you to see that this meaning is not inherent, not some law of the universe, but something you create. It becomes easier to let go then, to not cling.