Jack Dorsey, Tony Hsieh and David Allen know a thing or two about the importance of efficiency in business. Below, a few of their top productivity hacks that you can implement today.

No matter how long your to-do list grows, the length of a day stays the same.

It’s a challenge every business leader faces. While there’s no easy solution, the business world’s greatest minds have devised some creative techniques to help them get everything done.

Remember the rocks, pebbles and sand metaphor from Stephen Covey, author of The Seven Habits of Highly Effective People? The rocks represent the work that matters most to you, the pebbles represent smaller responsibilities, and the sand represents those trivial tasks everyone struggles with, such as organizing email or filing paperwork.

The point is that if you fill up your day with sand, you won’t have any time left for the big rocks. Wise time managers focus on their rocks first, then fill in the extra space with smaller tasks. Tech entrepreneur Bill Trenchard advises following the 80/20 rule: Spend 80 percent of your time on work that moves the needle and the remaining 20 percent on small stuff.

Below are some of the efficiency strategies top business leaders use to carve time out of their day for the work that matters most.

Theme Days

Even when you strive to concentrate on what’s important, distractions can pop up and derail your day. Square CEO and Twitter chairman Jack Dorsey avoids falling down the rabbit hole by establishing a theme for each day of the week.

For example, he devotes Mondays to management, Tuesdays to product development, Wednesdays to marketing and so on. Your themes might differ depending on what your “big rocks” are, but the goal is to use them to keep you on track.

“There are interruptions all the time but I can quickly deal with an interruption and know that it’s Tuesday and I have product meetings and I need to focus on product stuff,” Dorsey told Techonomy (Tweet this).

The Yesterbox System

Many CEOs cite email as one of their biggest time killers. In the time it takes to answer one email, you might receive three more. When you’re pursuing the elusive empty inbox, your day can fly by before you know it.

“There’s never a sense of completion, and it’s virtually impossible to get to the elusive goal of ‘inbox zero’ because as soon as I start sending emails, replies start coming back to me,” said Zappos CEO Tony Hsieh. “And even if I do get to inbox zero, which has happened less than 10 times in the past decade for me, it lasts only a few hours.”

To get off the email treadmill, Hsieh developed the Yesterbox approach to managing email. It’s a simple concept: Deal with yesterday’s emails today and leave today’s emails for tomorrow.

The advantage of this system is that you know each morning exactly how many emails you have to get through, so you can limit the time you spend managing email and ignore the distraction of incoming messages. Plus, you get a sense of accomplishment when you finally empty out yesterday’s inbox.

Related: 6 Awesomely Simple Ways to Spend Less Time on Email

Two-Minute Tasks

Efficiency isn’t just about how you handle the big stuff. It’s also about using your small chunks of time wisely. Time management consultant David Allen’s strategy is to keep a list of quick tasks you can finish during those brief windows of time that open up throughout the day. That way you don’t waste time thinking about what to do next.

“A lot of people procrastinate because they don’t know what their next action should be,” Allen told Success magazine. “Many times the next step is something that could be done fairly quickly. So the first thing to do is to make sure you’ve got everything broken down to the next action level.”

Two-minute tasks might include returning a voicemail, organizing email or purging old files—all the “sand” on your to-do list.

“The truth is a lot of things take less than two minutes to get done,” Allen said.

Mastering these efficiency strategies can help you manage an overwhelming workload without losing sight of the work that fulfills you. You may not be able to increase the hours in a day, but you can cut your to-do list down to size.

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