^ as dr-ripple said works for me. just concentrating on breathing, in out, sometimes if i have to visualise something in my head cause the md is still having an effect on my thoughts i picture the air going up my nostrils and then out again.
i used to use weed to get to sleep but it makes me anxious nowdays. breathing works really well, it may be obvious but stay completely still, don't keep shuffling around and you'll eventually fall asleep. Sometimes i wake up in the exact same position, i always have the lightest sleeps on md, mind is always very much awake.