Productivity can be hard to achieve and even harder to sustain. Modern attention spans seem to be getting shorter, even as the number of distractions around us increase. With that in mind, here are four tips for those of us who are looking to accomplish more in the limited amount of time we have each day:

1. Take care of yourself.

Did you know that food has a direct impact on your cognitive performance? If you don't watch what you eat, it's very likely that you'll find yourself unable to concentrate for long periods of time on things that matter. Instead of junk food like burgers, fries, and soda, fuel your mind with such foods as blueberries, fish, walnuts, and green tea, which are proven to deliver cognitive benefits.

Diet is undoubtedly important, but good sleep habits may be even more critical to boosting productivity. Focus, energy, creativity, and overall happiness are all negatively impacted when we deprive ourselves of sleep. One study of workers at large corporations revealed that people with insomnia struggle with time management, while another study from Harvard University found that American companies lose roughly $65 billion each year because employees don't get enough sleep. That makes sense -- productivity and sleep deprivation simply don't mix.

2. Minimize distractions.

There's no doubt that technologies like social media, smartphones, and smartwatches keep us connected, but they also make us distracted. When you have access to entertainment on demand and endless amounts of information at your fingertips, it's easy to avoid doing the things you should be doing. Before you set to work, try muting desktop notifications and turning off your phone. Likewise, designate a period of each day to concentrate on work, and tell your colleagues that you don't want to be disturbed during that time. Productivity is much more attainable when you minimize the external stimuli that tend to draw your attention away from the task at hand.

If your distractions are largely internal, help yourself stay zeroed in by creating a "distraction list." Whenever a distracting thought enters your brain, write it down on paper or in a Word document so that you can come back to it later. This tactic uses the same psychological principles as the popular Pomodoro Technique to help you stay on track when trying to complete a task. Experiment with a number of different strategies and see which ones work best for you.

3. Keep emails under control.

The death of email has been proclaimed countless times, and yet it remains the most popular method of workplace communication. For that reason, it's important to keep your inbox organized. Unsubscribe from promotional emails and newsletters that don't interest you, and when you receive important emails, handle them immediately. Some productivity gurus advise checking email rarely, but to keep work flowing, it's actually best not to procrastinate.

John Furneaux, co-founder and CEO of Hive, an AI-based project management tool used by brands such as Uber, Starbucks, Google, and Netflix, argues that people who only check email once or twice a day can end up causing operational bottlenecks. "I've read a ton of thinking on why you should only check your email twice a day," he says. "I don't know where those people work or what kind of job they have, but if they have any job in management, then they're making life difficult for those around them." Responding to emails promptly can keep you from falling behind and allow your colleagues to remain productive as well.

4. Have a plan.

Your ability to be productive on any given day often depends on what you do the night before. Before you go to sleep, make a list of important items to focus on the next day. Not only will this help you stay on track when you wake up, but it may also prevent you from losing sleep because you're preoccupied with the next day's responsibilities.

As you make your daily schedule, don't just include the work you need to get done. Schedule breaks and downtime as well. These periods of relaxation are key to maintaining wellness and overall productivity, so don't overlook them. The bottom line is that planning works. If you wake up without a plan, you'll spend a significant amount of time just trying to figure out what you need to accomplish.

Productivity can be a fickle thing. By remembering the tips above, you can put yourself into the best position to be productive on a consistent basis. It's OK if you're not on top of things every minute -- life can be chaotic. What's important is that you don't fall too far behind, and that you have a strategy for getting back on track when you do slip up.