There is one thing I forgot to mention in the original post.

When I am totally relaxed my eyelids seem to have a habit of opening very slightly, so I made a kind of sleep mask. Its actually a lenth of dark cotton material knotted to make a loop (high tech stuff) and worn over my head. The slight pressure helps to keep my eyelids closed and also cuts out more of the light from my window in the mornings, it could also help with preventing premature awakenings from LDing where there is some light entering the room.