What are the best productivity hacks of startup CEOs? originally appeared on Quora--the knowledge-sharing network where compelling questions are answered by people with unique insights.

Answer by Mikael Cho, founder of Crew | Unsplash, on Quora:

I'm the CEO of two startups. One was a happy accident that became one of the fastest growing photography websites. The other has yearly revenues in the millions and has grown an average of 300 percent year-over-year. To work on these fast-growing companies while enjoying other parts of my life, I've had no choice but to figure out how to be as productive as possible.

Being a productive CEO is not any different than being productive at anything else in life. It comes down to how well you manage the small choices you make every day.

Do you watch Netflix or do you go to sleep? Do you go to the networking event or do you write that sales email? Do you take that coffee meeting or do you work on your investor presentation? Everything you do has an opportunity cost.

Being a productive CEO is not about putting in the time. It's about putting time in the right places.

Your level of productivity is one of the best ways you can push your startup toward success. Startups are defined by growth, and growth is measured by a metric (usually revenue and users) over time. If you can manipulate time (i.e., do something better and faster) you create an opportunity to build a successful startup. By managing your time well, you may fit in that extra product experiment that unlocks more revenue. You may get a few more days to think of that marketing strategy that gets you significant exposure.

As a CEO, you have your hand in everything from sales to marketing to product to hiring to fundraising. There's way too much going on for you to put your attention everywhere at once. You have a limited number of decision-making points in a day.

This is why Mark Zuckerberg wears the same shirt every day.

"I really want to clear my life so that I have to make as few decisions as possible about anything except how to best serve this community," Zuckerberg said.

Deciding what to wear is a waste of time compared to deciding how Facebook will impact the billions of people who use it. Great CEOs like Zuckerberg focus on what will have the biggest impact, and remove everything else.

Maintaining good physical and mental health is also part of it. If you're in pain, you can't focus on being your best. If you have a back injury, for example, that will probably make you less productive because you'll be thinking about that pain rather than your work.

I've been a CEO for four years. I've experimented with many ways to improve my productivity. Here's the list of things I do now. Hopefully, there are some ideas here that might be useful for you.

1. Remove the noise.

  • Turn off your phone and computer notifications. Though many things seem urgent, they hardly ever are. Most things can wait a couple hours. Notifications are poison for your attention. Turning off notifications allows you to focus. We can't multitask. You might feel like you can, but what's really happening is your brain is switching between tasks. It's shutting down and restarting every time. Switching is inefficient.
  • Write everything down. I aim to keep my brain as empty as possible. I don't try to remember anything. It's harder to focus on one thing when you have thoughts, ideas, or tasks swirling in your head. Whenever I have an idea, I drop it into the Notes app on my phone and forget about it.
  • Automate anything you repeat. If you think you need to repeat something, write it down. We use the project management app Trello to document everything. We create step-by-step processes to automate tasks like setting up passwords, booking flights, or marketing a new feature. Don't waste brainpower repeating things over and over. Write it down once. Forget it forever.
  • Use fewer tools. Figuring out a new tool or switching tools takes time. You don't need 10 tools. Pick a few good tools that could be used for many things. Our company picks flexible tools that we expect to stick around. If you bet on a "hot" tool just because it's hot and you have to switch later, that'll cost you. Ninety percent of my day happens in four places: Google Chrome, TextEdit, Trello, and Google Docs.

2. Focus.

  • Chunk your tasks. As a CEO, you need to do and give input on a lot of things. To reduce the inefficiency of constantly switching between tasks, I set aside blocks of time to do similar tasks. I create repeating events in my calendar and block out a chunk of time from one to three hours, depending on the task. For example, I check our team messaging app Slack twice a day. The rest of the day, I quit Slack. I also bulk all my meetings together in the afternoons. Chunking tasks together helps keep your brain focused so you can do better work in less time.
  • Do focused work. Not all hours are created equal. Just because you work more hours doesn't mean you're doing more (or better) work. When we try to multitask, we might feel like we're getting more done, but as research shows, we actually do less and make more mistakes. One hour of focused work with no distractions is more valuable than three hours of interrupted work. When you're working on one thing, close your browser tabs and turn your phone to airplane mode. Put everything away except the one thing you're focused on. Sometimes I even work from my phone because it forces me to only see one screen at a time.
  • Remove the chance for interruption. It was hard when I first started working with extreme focus. I'd put my headphones on and ignore people if they spoke to me. I felt like I was being rude. Because I was thinking about my rudeness, my mind didn't focus on my work. I realized one of the mistakes I made was not telling people how I was working. Taking the time to tell people how you're working is much better than snapping at or ignoring people if they ask you for something while you're in focus mode. Both of these only lead to more stress, which ultimately hurts your focus. If you have kids and it's hard to remove interruptions, try adding a work session when they're asleep, early in the morning or late at night. Here's an example of what I send my wife before I go into a focused work session:

  • Start your day with quick wins. Sometimes you wake up and don't want to work. That first task on your list looks hard, or you feel tired. One way to overcome this is to start your day with a couple of easier tasks to get your momentum going. By simply opening my computer and doing something easy like cleaning off screenshots from my desktop, I switch my brain into work mode.
  • Win your morning. Our biological clock makes most of us feel most alert in the morning. Even if you don't wake up early, it feels good to start the day with the most important task. To find your most important task, think about yourself at the end of the day. If you only got one thing done, what task would make you feel most accomplished at the end of the day? Start your day with that.
  • Constrain the time you work. I work in one hour to 90 minute sessions, with untimed breaks in between. When researchers at Florida State University looked at elite performers, they found the best performers practiced in uninterrupted 90 minute sessions and rarely worked more than four and a half hours in a day. I can feel my energy level and focus dip as I get to the end of an hour of focused work. Constraining the time you work helps you stay focused. I used to set aside full days for focused work. The problem was that because I had all day, I would relax. This often led to procrastination. Now I use a timer to clock my work sessions, limiting them to the one hour to 90 minute range. If you feel like you have lots of time to do something, you'll find ways to fill that time. Often, this is by doing easier, less important things. By shortening the timeframe, you're forced to focus.

3. Maintain good health.

  • You don't have to workout every day. Just move. Though our bodies crave movement, you don't need a huge workout to get the level of exercise you need to be healthy. National Geographic researcher Dan Buettner studied areas of the world where people are living the longest. One thing he consistently found was the impact of constant, low intensity exercise, either from walking, standing up and sitting down, or tending to a garden. Staying in any one position for too long causes our blood circulation to drop. Moving gives you a moment to refresh. Whether it's walking to your office, taking the time to stretch while you're microwaving your lunch, or playing a sport, any type of blood flow acts as a release. It's an opportunity to refresh your brain.
  • Hang out with someone who makes you happy every day. People who make us happy make us feel good. If we feel good, we do better work. No matter how much I have going on, I prioritize my family. It makes me happy. When I get back to work, I feel fresher.
  • Make it easy to eat healthy. Eating well can help you work more efficiently. The challenge is that preparing and eating well can take up two or three hours of your day. That's a big chunk of time. The trick is to figure out how to eat well without all the prep time. Most meals I make take less than 15 minutes to prepare. I usually make two eggs in the morning and an avocado and salad for lunch and dinner, along with a protein source like fish. I order the same things from the grocery store so I don't think about what I should cook. This is my list of zero-prep snacks: dry roasted edamame, nonfat Greek yogurt, carrots, and easy-open cans of tuna. If you enjoy taking the time to cook, go for it. I do it sometimes. The feel-good oxytocin release can be a good break to fuel your work later. But if you don't have time, make it easy to eat well.
  • Use music to boost energy. Spotify conducted research on the benefits of certain types of music. Researchers found that musical tempo in the range of 50 to 80 beats per minute can help induce the alpha state in your brain, which is when your mind becomes calm and alert and concentration is heightened. If I'm about to do a repetitive task, like answering email, I listen to my favorite songs to get my energy up. If I need to do a complex task that requires focus, I listen to songs without lyrics to help me get and stay in a state of flow. Music can have a significant impact on your mood and thus impact your work efficiency.

This list of tips might make it seem like becoming productive means turning yourself into a boring robot. But that's the trick.

If you see the day-to-day schedule of most top performers (athletes, authors, CEOs, etc.), it looks boring. But that's the ultimate productivity hack. It may seem boring, but boring is how you clear space to do your best work.

Remove the unnecessary. Automate decisions. Maintain good health.

This question originally appeared on Quora--the knowledge-sharing network where compelling questions are answered by people with unique insights. You can follow Quora on Twitter, Facebook, and Google+. More questions:?