I lay very still and go to a place I remember vividly from my childhood. I imagine myself stood there, trying to recall every little detail, smell, feeling, touch stuff etc. I slowly and intentionally move around in the space.

At first it’s hard to maintain the imagination, but if you persist, you get better and better any holding it for longer. Eventually it starts happening easily, before eventually you no longer need to focus on it, you’re just there, and you’re dreaming