Basic sleep hygiene is a good starting point. Sleep on a consistent schedule 7 days a week. Use your bedroom only for sleeping. Don't read, work, or study there. Avoid eating right before bedtime. Get away from bright lights, emissive display devices, and loud noises for about an hour before you go to bed. Exercise is great too, but not right before bedtime. Do note that once you start using this routine it may take 4 to 6 weeks to really see the benefits.

SwellJoe's comments on caffeine and sugar are true. My doctor told me that caffeine has about a 10-hour half-life. After noon it's generally something I avoid.

If you try these things (or at least a good portion of them) and you don't see any improvement it's time to start looking at health conditions rather than merely poor habits. Sleep apnea is a major cause of chronic exhaustion. Restless Leg Sydrome is another. With both of these you are constantly waking up during the night and never attain the deep sleep needed to rest.

My father had sleep apnea - when he did an overnight EEG sleep study the doctors determined that he was waking up over 80 times an hour due to airway blockage. He started using a CPAP about two years ago. The CPAP is a face mask which generates positive air pressure to keep airways open. The difference was dramatic. He's much more energetic, much less grumpy, and has in general been much happier since he started using it.

I personally had awful sleep for years. I was perpetually exhausted. The only way I was able to sleep was to stay awake for 24 to 36 hours and then pass out for 12 to 18 hours. I was miserable. I finally broke down my pride and went to see a sleep specialist. I implemented the sleep hygiene strategies and saw slight improvements but no major gains. I didn't have RLS or apnea, so the possible suspects were narrowing down. On a long shot we decided to try a medication called Rozerem. It's a synthesized melatonin available as a prescription. In most people the pineal gland regulates the sleep/wake cycle via the production of melatonin. As it turns out I have extremely low melatonin production, so my body never got the signal to shut down and sleep. With the introduction of melatonin in pill form about an hour before bed I was actually able to get a good night's rest. The difference was astounding. I had forgotten what being rested even felt like. Interestingly the melatonin had an immediate dramatic effect on me. It doesn't force drowsiness like a sedative does. It allows me to feel sleepy (rather than just tired or exhausted). Rozerem won't do anything for someone with normal melatonin production however. Past a certain level the body just metabolizes the extra melatonin and it is neutralized. For the same reason increasing the dosage of the medication won't have any effect.

For me the combination of improved sleep hygiene and the synthesized melatonin made a dramatic difference in my quality of life. Treating my father's sleep problems made him a much happier individual. If your doctor thinks that a medication for RLS will help you attain better sleep, I highly recommend that you at least try his suggestions. There is no substitute for being well-rested and you owe it to yourself to find out what will allow you to gain a good night's sleep.