Here is some info you may find helpfull, I work in the nutritional supplement field and maybe this info can help you out.
Chronic insomina is often a sympton of a underlying medical disorder. Fifty percent of insomnia cases can be attributed to depression and other psychological disorders such as stress, anxiety, and grief. Some physical disorders that can grant chronic insomina include asthma, hyperthyroidism, kidney disease, hypoglycemia, and arthritis. Certain drugs like the antiseizure medication Dilantin can also cause this problem as well as certain antidepressants and decongestants.
There is also a disorder called restless leg syndrome which causes people to jerk there legs in bed, twitch and kick involuntarily.
IMO though, a good amount of insomina is due to a lack of certain nutrients in the body. To be specific calicum and magnesium. Try taking your calcium and magnesium before bedtime as calicum has a calming effect on the body and magnesium which is needed to balance with calicum helps relax the muscles. Try around 2,000 mg daily of calicum in divided doses, after meals and at bedtime, take this with 1,000 mg daily of magnesium.
Melatonin is also very good, 5 mgs should be taken 2 hours or less before bedtime, make sure your room is 100% dark, as light can affect the release of this natural hormone. Other nutrients to look at include a B complex with extra pantothenic acid (b5) which helps to promote a restfull state and fight stress. Vitamin C is also is very important in fighting stress and should be taken. Folic acid deficiencies are also linked to insomina.
For herbs, I would take a look at valerian root, chamomile, passionflower and kava kava to promote a sound sleep and get good REM. Try to find a combination herbel extract.
Its good to avoid heavy meals a few hours before bedtime, but its good to eat things like bananas, dates, figs, yogurt, tuna, milk or turkey before bed because these foods are high in the amino acid tryptophan. Also avoid caffeine after lunch.
Cheers