There are quite a few things that could contribute to overall energy levels, and they can be split into two categories: physical (sleep, exercise, and nutrition) and mental.
Physical
Sleep:
Get plenty of quality, uninterrupted sleep.
You want a comfortable bed in a cool, quiet, pitch-black environment.
White noise, like a fan or rainfall audio loop, can help block out miscellaneous sounds.
Sleep cycles run in 90-minute segments, so aim to wake up either 7.5 or 9 hours after you go to sleep.
Try to go to bed and wake up at the same time every day.
If you have trouble falling asleep, take 3 mg melatonin one hour prior to bed.
Limit alcohol use in the hours before bed, as the chemical prevents you from reaching a deep state of sleep. Caffeine has a 6-hour half life, so don't ingest any within 10-12 hours of bed time.
Caffeine is addictive and repeated use will raise your tolerance. Consider alternating with
modafinil in order to prevent tolerance to either drug from forming.
Get some sunlight every day. Your body's circadian rhythm uses it to determine regulatory hormone levels, and getting some midday sun can help your body slow down once night falls.
Don't exercise within several hours of bedtime. You want to slow down both mentally and physically in preparation of sleep.
Turn off fluorescent lights and anything with a screen at least an hour prior to bed, as the blue light will trick your body into thinking it's day time. Alternatively, grab a pair of
blue-blocking shades.
Exercise and Nutrition:
Try to get some exercise every day. I like to start my day with a
dynamic stretching routine to help get the blood flowing. I lift 3 days/week, and will either take a long walk or swim some laps the other days.
If you're fat, lose weight. The excess adipose tissue increases your estrogen, lowering your testosterone and energy levels.
Look into the paleo diet: meat, fish, fowl, eggs, fruits, vegetables, nuts, seeds. Cut out processed foods, grains, vegetable oils, and anything you might even remotely be allergic to, even on a cellular level (wheat, soy, dairy, legumes). The bulk of your diet should consist of quality protein surrounded by healthy fat and vegetables, with fruit and special exceptions like dark chocolate and red wine making minor appearances every now and then.
Cut your sugar intake as much as possible.
Drink water, tea or coffee. Eliminate soda and other processed drinks. If you drink alcohol, try to make it wine or something clean like vodka soda with lime. Ditch the beer.
Try caffeine naps by drinking a cup of tea or coffee and then taking a twenty-minute nap immediately after. The nap will refresh you but won't be long enough for deep sleep to take over; it will also clear out adenosine (which competes for caffeine at the molecular level) from the brain, providing more room for the stimulant.
Get some blood work done and pinpoint weak spots for supplementation. Almost everyone could use daily doses of fish oil (or some other source of omega-3s like liver or krill), as well as vitamin D in the winter months. A multivitamin probably couldn't hurt, although if your diet is on point this would be unnecessary.
Quit watching porn. Quit jerking off. Personally I find sex to be energizing, although some would dispute that and say it makes them tired. YMMV.
Don't sit or stand for extended periods of time. Move, frequently, as much as possible.
Mental
Work on your intrinsic motivation. You need a reason to get out of bed every day. Pick several worthwhile, achievable goals and commit to working on them every single day.
Read
Flow by Mihaly Csikszentmihaly and structure your life so that you can enter flow as much as possible.
Read
Drive by Daniel Pink. The building blocks of internal motivation are autonomy, mastery, and purpose. Find something you believe in, work towards becoming an expert in that field, and find a way to achieve independence.
Watch your negative self talk. Don't let your intrinsic
negativity bias take over. Find an affirmation, motivational quote or the like and hang it up where you'll see it every day.
Success breeds success. Instead of focusing on big wins in the distant future ("I will lose 20 pounds by next year") focus on little wins today ("I will walk 20 minutes after lunch").
Don't let a lack of organization and clutter (both mental and physical) detract from your energy levels. Clean and organize your office/workspace. Create a productivity system that you trust completely and outsource all your to-do's to it. Don't let mental notes and reminders drag you down; get them on paper or into the system so you can focus on other things.
Don't multitask. Focus on one task at a time before moving to the next.
Keep stress levels low. Find time for the important relationships in your life and invest in them. Get off facebook and social media and spend time with friends and family in person. Find an LTR-worthy girl who supports you and date her while investing your energy in personal endeavors. Look into meditation or other techniques for calming the mind.