How about acupuncture?
I've had trouble with light sleep... waking often during the night... etc... and after the normal things (regular exercise, avoiding caffeine, drinking plenty of water, getting into a good routine, valerian, camomile etc) I am trying acupuncture. I've only been for a couple of treatments so far but I've noticed even with that, that if I wake during the night, I can fall back asleep more easily. Apparently it works for some people, not for others ... but maybe that's worth a shot?