Try to feel your dream body and then try to feel the connection between your dream body and your desired dream scene (the ground, the air, ect.) Then, try moving around in the dream scene that you feel. Let everything else in the dream form around your sense of touch.

Alternatively, you could focus on some other relatively small, easy part of the dream to focus on and let the dream form around that.

If the dream isn't forming around something you're focusing on for some reason, find something else to focus on.