I think you asked this before.
One trick I've found that works for me is to add a bit of "up" to my "down". Drinking chamomile or sleeping tea doesn't do much for me, but using one bag of chamomile and one or two bags of regular caffeinated tea relaxes me a lot.
Two bags of green tea for each bag of chamomile in as many cups of water as green tea bags works great for me, but I suppose the dosage depends on the person. I'm a caffeine junky myself, so...
The subtle flavour of the green tea goes really well with that of the chamomile. I'm drinking some right now, getting ready for bed. Delicious.