I'm quite prone to having trouble getting to sleep, waking up more tired than when I went to bed, and tossing and turning and waking up during the night. In the quest for the sometimes elusive good night's sleep I offer the following tried-and-true tips:
Don't drink beforehand
This is quite an important point. Nothing wakes you up more effectively in the middle of the night than a full bladder. Some water or milk is probably okay, to avoid dehydration, especially in hot weather, but four glasses of beer will inevitably have you up at 4am with a pressing need.
Also, avoid any consumption of caffeine for several hours beforehand. Coffee or coke before bed will impair your ability to fade into slumberland. Cigarettes will also keep the shut-eye away for a short while as well.
Ensure your bed is at an optimum temperature
This shouldn't be too difficult to achieve - it's just a matter of the right balance of blankets, sheets, quilts, etc so you don't freeze or overheat. Electric blankets will help get your body heat started if the weather's a bit chilly.
Get to sleep at a reasonable hour
This one is pretty obvious. There's no point in attempting to get a good night's sleep if you have to get up in five hours anyway.
Possibly easier said than done, but a perfect way to lie wide awake all night is to be tense or have a lot on your mind. As clichéd as it sounds, thinking about something calming can be a real help. Your favourite music at a low volume is also useful. And there's no turning one's nose up at a light sedative like valerian root to get you over the hill to the other side.
Also, going to sleep if you're all wound up about something is your ticket to bad or unsettling dreams of the kind that you wake up in the middle of the night from.
Don't eat beforehand
This may not apply to everyone, as I have known people who cannot sleep on an empty stomach, but I have personally found that eating too close to bedtime affects my ability to get to (and stay) asleep.
Where possible, non-soothing noise should be eliminated
A dripping tap may not wake you up but it will certainly try its darndest to keep you awake if you're having trouble drifting off. Invest in a new washer if need be. And turn off any happily humming appliances that don't need to be on while you're asleep, unless you find the hum to be soothing.