It can take months of active practice to have lucid dreaming.
The liminal state takes about five minutes to learn. The article has a story about Thomas Edison dropping balls on the floor; this works well.
The process of falling asleep feels like having my mind squeezed through a narrow gap, surrounded by random proto-thoughts like fragments of words and images. I wonder if that’s just my perception of the lower frontal lobe activity they describe in the article. Once I’m out on the “other side” in a dream, I feel like my mind can stretch out and relax again.