To clarify and deepen my understanding of the Moon, I pondered the following comparisons with similar and/or opposing cards. Maybe my comparisons will inspire you to make your own!
Mental
Issues
Moon: Mental/emotional issues to do with the "dark" part of our soul - fear, sadness, needs. E.g. phobias, depression, PTSD. Also: Sleep disorders.
Clouds: Problems which arise from a clouded view of reality, e.g. misunderstandings; lack of understanding, disorientation; illusionary thinking, hallucination, or paranoia.
Birds: Issues to do with extreme stress, worries, difficulties with concentration: e.g. nervousness, anxiety, obsessive compulsive behaviour, ADHD.
Sadness
Moon: Melancholy and depression - sadness which arises from the perception of the whole world as a dark place.
Coffin: Grief - the type of "sadness" specific to the experience of a loss.
Moon vs. Sun - total opposites
Moon: Darkness, night, winter and autumn. Sadness, that of which we are only half- or even unaware; profoundness.
Sun: Light, day, spring and summer. Happiness, awareness, obviousness, possibly: superficiality.
