Often, good liminal space fiction focuses on a specific feeling, or set of feelings. "Loneliness", "fear", and "Eeriness" are common choices, but the sky is the limit when it comes to capturing the human experience. Choosing an emotion which is a bit obscure, or an unexpected topic relating an emotion, can make for a very unique article. Here are some examples to get you thinking: "drowsiness", "comradery", "impatience", "decay". These aren't emotions commonly associated with liminal spaces, and some may not even be emotions by the traditional definition, but they can all be conveyed with writing.
“No one ever told me that grief felt so like fear. I am not afraid, but the sensation is like being afraid. The same fluttering in the stomach, the same restlessness, the yawning. I keep on swallowing.
At other times it feels like being mildly drunk, or concussed. There is a sort of invisible blanket between the world and me. I find it hard to take in what anyone says. Or perhaps, hard to want to take it in. It is so uninteresting. Yet I want the others to be about me. I dread the moments when the house is empty. If only they would talk to one another and not to me.”
― C.S. Lewis, A Grief Observed