The guidelines for getting a healthy sleep are as follows:

Get regular daily exercise. This is one of the best ways to ensure healthy, good-quality sleep. When you exercise, your body temperature fluctuations throughout the day become more accentuated. This allows your body to achieve the deeper stages three and four sleep, which are more rejuvenating for your body.

Stick to a schedule. Go to bed and get up at the same time every day. Going to bed at the same time every night is not as important as getting up at the same time every day.

Avoid alcohol at night. Alcohol is sedating; it induces stage two sleep, but it disrupts the deeper stages three and four. It is also metabolized quickly, over a one- to two-hour period and, once metabolized, causes the release of a pulse of epinephrine that is stimulating and often wakes you up.

Try to limit caffeine to no more than two cups of coffee before noon. Caffeine is metabolized slowly, with a half-life of up to 7 to 12 hours. This means that if you have four cups of coffee in the morning, you may still have the equivalent of two cups of coffee in your system when you go to bed at night.

Have a bedtime ritual. Avoid paying bills or checking e-mail right before you go to bed. Stimulating mental activities right before bedtime make it harder for the brain to slow down and shift into sleep mood. Consider a warm bath as part of your bedtime ritual.

Reserve your bed for sleep and sex. Don't use your bed to engage in mentally stimulating activities. You want your brain to associate your bed with relaxation and sleep.

Get rid of night worries. If you tend to wake up in the middle of the night with racing thoughts or worries, keep paper and a pen by your bedside. Without even turning the light on, you can jot down the thought that woke you up. Tell yourself that you are going to let it go until the morning.

Don't smoke. Nicotine is a stimulant. Smokers who stop smoking notice that they sleep better.

Check your medications. Over-the-counter medications such as decongestants can be stimulating, as can some prescription medications. If you have trouble sleeping, talk to your doctor about whether you should take your medication in the morning or in the evening.