Too many people erroneously assume that you can just lie down, and you'll automatically fall and stay asleep. That's sadly not true for many of us, and this issue tends to worsen as we age. You need to put some effort and preparation into your nightly sleep hygiene. The great news is that we can work to optimize sleep. The strategies below will help improve both the quality and quantity of your sleep.

There is a lot of information below! Start with this summary and fill it in as you need to with the details presented after that.

Summary:

Try and be awake, stimulated and active with the sun and prepare for sleep as it darkens.  Attempt to limit daytime naps to 40 minutes.  Avoid TVs, phones, screens in the sleep room.  Keep the bedroom cool, relaxing, and comfortable.  Minimize food and fluids within 3 hours of bed.  Consider relaxing music, meditative words, ambient noise and aromatherapy around bedtime.  Completely darkened the room at night including phone chargers and other tiny little lights.  Supplements can be helpful.  Start with melatonin 1 to 2 mg nightly (generally more is not better) and Magnesium threonate 500 mg.  These are safe and can be used together, and also with virtually any prescription medication.  Effective prescription medicines are available for short term but have more side effects, and sometimes are associated with increase in dementia later in life.

• Try to stick to a regular sleep schedule. It's not always possible because of family or work responsibilities but do your best to have a regular bed and waking time. Ideally, we should begin to wind down as the sun is setting.
• Our ancestors naturally began to prepare for bed with the sunset and awoke with the sunrise. Try to follow this pattern as your schedule permits. A lack of sleep can lead to the need for a nap which can impair the quantity and quality of your restorative sleep.
• Your goal is to achieve seven to eight hours of quality sleep. Research shows that people getting less than six hours and more than nine hours are negatively impacted. (Children need more.) The idea that older adults need less sleep is a not true.
• Refrain from caffeine (or other stimulating beverages or supplements) past the early afternoon. Work to determine which supplements are stimulating and be sure to include them in your morning stack.
• Eat your last meal of the day at least 3 hours before bed. This promotes autophagy, which cleans out cellular waste products to use for cellular renewal. It's also much easier to sleep on an empty stomach.
• If you struggle with sleep, this is another reason to refrain from alcohol. The sedative effect of alcohol may seem to help, but research shows that it powerfully fragments sleep; dramatically disrupting your REM sleep cycle and depriving you from the restorative effect of sleep.
• Refrain from exercise within three hours of bedtime. Exercise ramps up adrenaline and prevents sleep.
• Take your supplements/meds a few hours before bed with as little water as possible. While it's important to hydrate during the day, you want to avoid bathroom runs during sleeping hours.
• No stimulating activities or conversations several hours before you plan to sleep.
• Transform your bedroom into your sanctuary. Keep it clean, uncluttered, free from work and any other projects.
• Arrange to sleep alone if you know you'll be interrupted at night. This is especially important if you and your partner have different sleep habits due to work or other demands.
• Avoid TV in the bedroom. We know this is aspirational for some. If you must watch TV, use the sleep timer so that it will automatically turn off. Also, consider the use of a blue blocking vinyl overlay that you can apply to your TV screen at night. (Details below.)
• Minimize low level radiation in the bedroom. Mounting evidence suggests that electro and magnetic fields (EMF) radiation (including WiFi) can impact overall health negatively. Make sure any electronic device in your room is either turned off, placed as far from the bed as possible, or placed on airplane mode when you go to sleep.
• Many people fall asleep reading. We know that the simple act of turning off your lamp can reawaken you, making it harder to fall back asleep. And, sleeping with the lamp on will disrupt melatonin production. For that reason, consider using either an eBook or tablet, that lights up (set to the dimmest setting), with an automatic shut-off feature so that you don't have to turn off the lamp as you drift off to sleep. Be sure to pick a device with a blue-blocking program, like Night Shift for iPads. If your model is older or doesn't have a compatible blue blocking program, you can use a blue blocking vinyl overlay that you can easily apply before bed. For those who prefer to read an actual book, consider an inexpensive red incandescent lightbulb or a blue blocking LED light bulb for your bedside lamp. Vinyl screens, specialty light bulbs and more can be found at Low Blue Lights.
• Some people prefer to listen to a gentle voice with soothing background sounds as they drift off to sleep. There are many apps designed just for this purpose. Calm, Pzizz and Headspace are a few that offer sleep stories, guided sleeping, and “sleepcasts”. Click on each to learn more. To reduce Wi-Fi exposure, only listen on airplane mode. (Calm only offers this for Android devices, but you can pre-download products for iOS devices.)
• Completely darken the bedroom or use a sleep mask. Any small bit of light during the night will interfere with melatonin production.
• Consider a warm shower, bath, or even a sauna before bedtime. The transition to cold air following exposure will help to make you sleepy.
• Keep the bedroom cool. Research shows that the temperature should be around 65F for optimal for sleep. Feel free to adjust up or down a few degrees to suit your preference. If you tend to be cold, be sure to have a warm blanket to cover up.
• If you feel wasteful cooling the whole house at night, consider using a mattress cooling pad. Ooler, $1300, Bed jet 3, $400 and Chili pad system, $600 I will allow you to chill your under blanket sleeping area to 65 degrees.
• Try a weighted blanket. Babies who are swaddled sleep more deeply and some adults report a similar effect with a weighted blanket. This strategy is most effective for those who struggle to stay warm although “cool” versions are available for warm weather. This is particularly helpful when using a cooling mattress pad.  These may not be so good for frail elderly people especially with breathing problems.
• Try a white-noise machine if you're regularly interrupted with extraneous noise from your heating system, air conditioner, outside traffic, neighbors, etc. Many have relaxing nature sounds (like rain, wind, or waves) that you can set to your desired volume to drown out bothersome noise.  You can also use fans either built-in or brought in for this purpose.
• Consider aromatherapy. Lavender essential oils have proven helpful in slowing heartbeat, relaxing muscles, and promoting slow wave sleep. Put a few drops on a cotton ball near your bed to see how it affects you.  Several other essential oils are helpful with sleep and relaxation and it is very inexpensive to use these in an aromatherapy device near the bed at night.

Healthy and safe bedtime supplements

Magnesium Many people are unaware that they're deficient in magnesium. This mineral is necessary for hundreds of biochemical reactions in the body and, most importantly, critical for brain function. Magnesium has sedative properties. Taken before bed, magnesium decreases circulating cortisol, increases melatonin, and improves sleep quality. A more neurally bio-available form of magnesium, magnesium threonate, has been shown to improve cognition in older adults.  Dose: 500 mg

Ashwagandha This herb, commonly used in Ayurvedic medicine, is an adaptogen that helps the body adapt to stress and exerts a normalizing effect upon bodily processes. Ashwagandha has many health benefits including stress reduction that leads to improved sleep. A recent study has found that triethylene glycol, found in the leaves of the plant, is responsible for the sleep induction effect. Ashwagandha has also been found to improve memory in people with MCI as well as improving executive function, attention, and information processing speed.  Dose: 500 mg

Bacopa monnieri This is another Ayurvedic adaptogen that, among other effects, increases acetylcholine, and improves cognitive performance. It may be particularly helpful for those experiencing trouble sleeping due to stress. Be aware that it can have a paradoxical energizing effect for some people. Be sure to initially experiment with a low dose (100 mg) taken several hours before bed to test how it works for you.

Tryptophan This is an amino acid, naturally found in many foods, including milk, eggs, poultry, and fish. Trytophan is the precursor to 5-HTP, which can be converted into serotonin, a neurotransmitter and key player in modulating the gut-brain axis, linking cognition to the gastrointestinal tract. Serotonin is also a precursor to the hormone melatonin, which helps your body regulate sleep and wake cycles. Tryptophan, taken in the middle of the night, can be particularly helpful for people who awaken and have trouble falling back asleep.  Dose: 500 mg

Gamma aminobutyric acid (GABA) is a naturally occurring amino acid that works as an inhibitory neurotransmitter in your brain, providing a calming effect. It may be particularly helpful for those with stress or anxiety.  Research has uncovered that GABA supplementation may help to improve working memory. GABA is often low in those who experience frequent insomnia and disrupted sleep.  Dose: 100 to 300 mg

L-theanine is an amino acid found in tea leaves. Paradoxically, it improves sleep quality when used as a supplement.Some evidence suggests that L-theanine helps with attention, focus, and reaction times. L-theanine has also been found to reduce blood pressure and boost immunity. If you decide to experiment with L-theanine as a sleep aid, be sure to use it in supplement form as the caffeine from tea may counteract the calming effect.  Dose: 100 mg

Melatonin Melatonin is a naturally occurring hormone that decreases with age. Supplementing has been shown to promote better quality sleep, not through a sedative effect but rather by encouraging a healthy circadian rhythm. Melatonin can also improve mitochondrial function, reduce levels of tau, and improve cognition in an Alzheimer's patients.
Dose: 1 to 2 mg

Prescription medicines are available and are sometimes effective.  Common ones that are used are trazodone 50 mg, mirtazapine 7.5 mg, Seroquel/quetiapine 12.5 to 25 mg, and doxepin 5 mg.  Each of these have their pros and cons. Consult with a doctor to determine what might be best for you.

The common prescription sleep medicines Ambien/zolpidem, and any of the benzodiazepines (diazepam, lorazepam, clonazepam) are not generally recommended unless you are treating significant anxiety as well.