I agree with mellow's tips, & would like to add also: taking a nice hot bath ('specially while drinking some herbal tea like chammomile). I personally like to go to bed a lil high & put the radio on 'sleep' (where it automatically shuts off) for 20 minutes or so... I always listen to the BBC, lol!

Maybe try acupuncture? It's been known to help with insomnia.