In today's interconnected and increasingly mobile world, people need no longer be confined to their offices. You can work anytime you like wherever you happen to be. But that very freedom has also resulted in some very bad habits that sap your productivity and can make you miserable at the same time.

That observation comes from productivity expert Maura Thomas, founder of Regain Your Time. Here are the habits she says can hold you back--as well as the people who work for you.

1. Working during your vacation.

"With your office in the palm of your hand, it is easy to check your email, respond to a text or call into the weekly conference call on mute," Thomas says. Too easy. Not only are you doing yourself a disservice, you're signaling to your employees that they have to work during their own vacations. "Knowledge work requires a fresh perspective, but you can't get a fresh perspective if you never step away," Thomas says.

2. Not using all your vacation time.

There's quite a lot of scientific evidence that skipping vacations is bad for our productivity, our mood, our relationships, and may even shorten our lives. So make sure to use all your time off, and to unplug from the office while you're away. Encourage everyone who works with you to do the same. "You'll get all the restorative benefits of vacation yourself, and you'll be modeling healthy behavior for employees," Thomas notes. (If yours is one of the growing number of companies with unlimited vacation policies, make sure you take at least two to four weeks off per year.)

3. Working during evenings and weekends.

We're all guilty of this--I'm writing this column late in the evening right now. But if you never step away from work, you never get the fresh perspective that only a mental break can give, Thomas warns. Worse, your employees will feel obligated to work similar hours. "Although leaders aren't looking to make employees feel as if they are tethered to their job at all times, it can easily happen," she notes.

4. Sending emails and texts outside business hours.

Doing this is absolute proof that you're working at all hours. And by communicating with employees at such times, you're encouraging them to answer you instead of taking their own time off. This is why a growing number of countries are making after-hours email to employees illegal. "If the issue isn't urgent enough to pick up the phone, then think twice about sending emails and texts at night, on the weekend or while someone is on vacation," Thomas advises.

5. Creating lists of priorities.

"To-do lists that include items with a priority of high, medium, or low don't give you enough direction," Thomas says. "A lot of times, we'll put a task on our to-do list that's just too big. 'Research local non-profits sounds' big and difficult and is more likely to be avoided. Instead, write down: 'Google non-profits in Texas.'"

This one small change can save you an enormous amount of wasted time wandering around the Internet or trying to figure out how to get started on a daunting project, she says. To really increase productivity, give each task a due date, but be realistic about how much you can get done in a day, and build in time for unexpected tasks or priorities to arise.

6. Multitasking.

There's plenty of evidence that multitasking is bad for both you and your productivity. Don't do it! Instead, Thomas advises creating conditions that allow you to focus completely on one thing. "Find the place where your attention is so absorbed in a single task that time moves differently, and you come out on the other side with a genuine feeling of accomplishment," she says.

This may mean posting an "unavailable" status on your chat clients, logging out of email, closing your office door, turning your mobile phone to airplane mode, and maybe even putting on headphones playing white noise. "Put yourself in a distraction-free bubble so you can single-task, even for just 15 minutes every hour," she advises. You'll be more productive, and happier too.