I will second (or third? fourth?) the music idea. I think, though, that a lot of it is simply inborn. We actually ARE one of those families who are
very into routine. My kids (well, not the 21- and 19-year old, but the 11 and 10 year olds) go to bed the same time almost 365 days a year. We've had the same routine in place pretty much their entire lives. It's snack, pjs, teeth, shower/bath if needed, and read for half an hour. We don't use electronics before bed, we do everything that the sleep specialists suggest. Ds11 takes after dh and can turn his palms up, take three deep breaths, and he is out like a light. Ds10 has a mind that keeps going and going. The older kids were like this too - one is still a horrible sleeper and one is quite good. Ds10 is just getting to the point where he is sleeping better and more consistently. The CDs made for sleep (supposedly in tune with your sleep brain rhythms but at the least relaxing music) really did help. Someone lying with him helped enormously too, but of course, that can get old. I honestly think that it's no surprise that my two more creative, less-structured, fanciful kids are the ones with trouble sleeping.
I don't know how creative I was as a kid, but I had the same problems. I used to call my dad collect at 2am (my parents were divorced and my mom and stepdad were too busy and tired to put up with this nonsense) to ask questions about death, or the universe, or God (this explains why I pretty much forgive any parenting mistakes my dad has made - what parent puts up with years of 2am collect calls, lol??).
Massage also helped with both my bad sleepers - again, time from a parent, but it does seem to really relax them. I guess the good news is that when I thought it would never improve, it finally did. So, if you survive another six or seven years, you too can have a passably good (but not great) sleeper. Sorry.
