Or better yet - this helped me more because I couldn't get what you were saying until I saw it - is that you can think of either one of two faces that the cube can sit on. Before I explain which faces I am talking of, I have to note that a cube face can be described by its diagonal, which is what I have to do to explain this in words and the second one is that in a drawing of a cube there are six peripheral intersection points(three to the right and three to the left) and two inside points a right one and a left one. So these two faces the cube can sit on are:

The first is the face whose diagonal starts from the bottom left peripheral point and reaches the right inside point

Then the second face is the one that spans from the left bottom peripheral point until the right middle peripheral point.

This helps me change perspective instantly.