Alot of the times your mind thinks without you, and it keeps me awake. Thats what happens to me. My brain just keeps going and I cant sleep. I eventually trained myself to space out and clear my mind of thoughts, thus putting me to sleep.
Another technique is beating your meat then passing out shortly after.
Do you ever take naps at all during the day? Try really hard to avoid that. I used to be REALLY bad about coming home from work, sitting on the couch, and falling asleep in front of the TV for an hour or so in the evening. It's always really hard to fall asleep for real after you've done that, even if it's just nodding off for a few minutes.
Unfortunately, I can't give a ton of advice. I've had sleeping problems for years and haven't really been able to do much about it. I went so far as to totally drop caffeine, and even that made no difference for me.
The only thing that's ever helped me were the pain pills they gave me when I almost broke a rib once. That shit knocked me right out.
Exercise more often if you don't already. Try reading a book. Turn off anything electronic about an hour before you go to sleep (computers are a big problem with this). Don't eat anything at all within a few hours of going to bed. You can also try writing out anything that's on your mind and bothering you somewhere. It doesn't matter how long it is or what it is even about.
I"m pretty weird when it comes to falling asleep, once I fall asleep I can keep on sleeping, like, I'm pretty sure I could probably sleep 8 hours, wake up, go back to bed and sleep a few more, and repeat. As for falling asleep, I can have a beer and fall asleep in two seconds on the couch in the right conditions in the middle of the afternoon and shit like that, but sometimes I'll be tired as hell at night and I still won't fall asleep any time quickly, but I think a lot of that is because I do a lot of thinking that keeps my mind going. Anyways, here are a few things I do/try to do that personally help me out
-I sleep with a fan on every night, even in winter I have it on low...I don't really even need it, it's more of a comfort thing. Helps a lot, and it also drowns out a lot of noises that would probably piss me the hell off, like barking dogs or cars driving by pretty fast.
-I will watch documentaries from my bed without the volume blasting. Makes me sleepy every time.
-Reading or even writing, particularly in a low-light setting, has helped me more than anything. Unless the book is really engaging, which I try and avoid doing if I'm trying to get to sleep, give me just a few minutes of trying to read when I know I'm fairly tired is going to make me say 'screw this' turn off the light and fall asleep pretty quick.