It's funny to get older and finally learn lessons that have been drilled into me since I was old enough to listen; but that's life.

Sleep is very, very important. It determines baseline more than any other factor. Good sleep creates the possibility for a good day. Poor sleep almost guarantees a bad or at least difficult day.

Bryan Johnson, the nighttime erections guy, says:

Make sleep your #1 priority. Nothing influences your conscious existence more.

I don't agree with him on everything, but on this, he's right.

So, how do I get good sleep?

Cold, but not too cold. You'll hear people say 69 is the optimal sleeping temperature. It's a reasonable statement, but it's incomplete. Insulation and convection need to be considered as well. What are you wearing? What's your bedding like? Is air circulating (fan)? These factors affect your body's ability to regulate temperature. If your room is 69 degrees and you're sleeping naked under a fan, you are losing much more heat than if you are wearing fleece pajamas under a heavy duvet.

If you have light when going to sleep, it lengthens sleep latency and worsens quality.

I am not a fan of blackout curtains aesthetically. They also have the significant downside of removing the sunlight stimulus for waking up. However, I do use them. I also use a sleeping mask. When I travel, a sleeping mask is as important to me as my toothbrush.

This is highly personal. Most nights I fall asleep listening to lectures designed for this purpose. Typically they are 2 hours long, so that it turns off once I am asleep. My earbud then falls out naturally during the night.

Sound rouses me easily. I am especially sensitive to leaf blowers, snoring and the Outlook email notification sound. To combat these enemies I keep earplugs by my bed and if I awake too early, I will put the earplugs in and go back to sleep. Earplugs with designs that lay flat against your ear are recommended if you lay on one side of your head. When traveling, earplugs and especially noise canceling earbuds are as important to me as my sleep mask. Noise cancelling is very good to have, because it actively cuts out frequencies that earplugs may not handle well, and you can never predict what those will be.

Unfortunately nothing works against snoring. It has complex frequencies, irregular patterns, and constantly changing amplitudes that make it difficult for the mind to tune out. I typically politely, but directly, ask up front if someone snores and don't sleep around them if so. Exceptions may be made, very rarely. Inquire within.

Fasting increases alertness. Adequate calories are necessary for good sleep. If the body senses that it needs energy more than sleep, guess what.

Mattress, choice of bedding, and especially a weighted comforter make a difference.

Alcohol universally degrades sleep quality. If you think it doesn't apply to you, you are wrong. Get a sleep tracker and compare.

Melatonin works well for me when I need to buff my sleep. I typically use it when I know ahead of time I will have difficulty sleeping, or when I need to pull my sleep time back 3-4 hours, and don't use it otherwise to avoid building a tolerance. Microdosing is key, 1mg or less is sufficient. https://news.mit.edu/2005/melatonin. I am careful with it, because taking too much or too late produces sleep inertia that lasts something like 12 hours after I wake up, which ruins my day and defeats the whole point of getting good sleep.

Diphenhydramine is a last resort if I absolutely need to sleep and cannot. 50mg usually does the trick without significant side effects. It is in my essentials kit when I travel.

Cannabis degrades sleep quality in regular users https://pmc.ncbi.nlm.nih.gov/articles/PMC7572650/. Most regular cannabis users will argue the opposite. For me it's generally a stimulant so I avoid it. CBD seems to help, but frequency, dosage, tolerance etc are murky to me and it seems quite inconsistent, so I typically avoid it.

Never tried hypnotics (ambien etc). I hear they are bad.

All of the above are important. But by far, the most important factor is

Being Tired

Shocking, right? If you are tired, you go to sleep more quickly and sleep more deeply.

Do you know what the best way to get tired is?

Exercise. It's fucking exercise.