All it takes to increase workplace productivity is to have happy employees--at least according to a recent study at the University of Warwick in the U.K. It found that in "three different styles of experiments, randomly selected individuals are made happier. The treated individuals have approximately 12% greater productivity."

Sounds easy enough to do, except you need to know what actually makes employees happy. And it's not necessarily about money. Here's what was found that has worked in making my staff happier each day:

Let them work from home when they need that flexibility.

Much of the stress in staff comes from trying to figure out how to balance their work and home priorities. With commuting traffic often eating into the time they could be taking care of appointments and errands, realize early on that it is OK to let many work from home a few days a week or even to hire completely virtual staff.

By treating them like adults and trusting that they will get their work done, it provides them with a way to improve the balance and take care of those other things weighing on their minds. Rather than be stressed out in the crazy traffic to and from the office, they are at home, being productive and happy to multitask by taking care of both work and personal needs. With the reduction in stress, there are a lot happier employees when they do come into the office.

Provide a relaxed work environment.

A relaxed work environment is one where all your workers know they can put their feet up on the desk, get in a quick game or nap on a break, and catch up with their social networks--within reason. No one is happy when a work environment is not just strict, but stifling as well.

At the same time, it can't be so relaxed that people forget that they need to do their jobs. Instead, strike a balance that provides your employees with enough "fun" and "social" time to keep them happy. After all, just focusing on work doesn't necessarily encourage creativity, but giving them the freedom to do other things while in the office does help put them in the right frame of mind to innovate and ramp up their productivity.

Encourage them to exercise.

Exercise not only gets the blood pumping and helps with physical health, but it also promotes a more positive outlook. Science has given us all the proof we need about the hormone recalibration that occurs during cardio activity, which releases those endorphins that fuel happy vibes. Beyond that, tell them they must get up and walk away from their desks for at least a half hour without their phones and walk or use the gym equipment.

Getting them out of the work space and helping them to clear their heads with fresh air and a different outlook seems to help employees handle the continued stress and challenges or problems that have to be faced. The stress gets worse if employees are tied to their desks. Walking away from it all and maybe even sweating a bit alleviates the frustration and potentially helps with solutions. A happier employee is the result.

Insist on laughter.

We all need to laugh, and it's the kind of medicine that can be used and passed around at work. Jokes and making jokes and even a certain dose of silliness are the reason for the saying, "If I wasn't laughing, I'd be crying." It feels good to laugh and alleviates stress or shifts the focus on something that may be bothering a person. Include activities at work that get people laughing at each other and themselves. It's a great diversion and brings the smiles.

Challenge them.

There is nothing better than seeing people's look of satisfaction after they have accomplished something that they thought they could never do. Give employees challenges that get them to stretch and improve their skill sets and knowledge bases. Whether they succeed or fail a few times with the challenges, let them know they are doing a great job and encourage them to keep trying. This tells them you want them to grow, professionally and personally, and will empower each person on the team.

Include them in company decisions.

People like it when you ask their opinion and let them know that it counts. They feel happy knowing that you think they have the talent, knowledge, and skill to contribute. In return you'll get some great ideas that raise the bar on where the company is headed. When employees are in the loop and feel that they are a part of something rather than just working for someone else, things will really progress in your company.

Spend time with employees.

Hang out with the people who work for you including taking the time to grab a coffee, go to lunch, or be beat on the Ping-Pong table. These are informal opportunities to hear what is on their minds, whether it is about work or home life.

You'll get a better sense of who they are and be able to use those personal facts later on. Surrounding yourself with these amazing people will also help you become a better person. You'll learn things about yourself you would have never known otherwise--not to mention that they appreciate that you've taken the time to spend with them as well as to listen intently about what makes them unique. Appearing to be less of a boss and more of someone who is just overseeing the company helps. You'll be less intimidating when you both get to know each other, and don't have to spend time reminding them of who is in charge.

Minimize meetings.

Let's face it, no one really likes meetings because they take up a lot of time when the work needs to be done. Meetings are boring, so limit them and find other ways, like online collaboration tools and quick informal check-ins, to get progress reports and answer questions or concerns. Employees are then happier just getting their work done rather than agonizing over a PowerPoint that they have to present or feeling frustrated about the amount of time wasted having a meeting about another meeting. This is something I try and work through every Sunday to prepare myself for the week.

Reward and recognize employee effort and achievement.

Everyone loves rewards and personal recognition. With information you gather from each employee while hanging out, you can customize a particular reward that he or she might receive for helping meet a target or even exceeding those expectations. Not everyone wants a gift card or a bonus, but personalize the experience as much as possible and all workers are happy to get something you've personally supersized to make it something they would really enjoy for all their efforts.

Provide benefits they need and want.

Underlying all employee concerns is that they make enough money to make a life for themselves and their families, but they also want to know that other needs or wants could be covered. When these needs and desires are taken care of, they have less to worry about and are therefore happier. Regularly review the types of benefits you offer and add to your already attractive benefits package to ensure you're offering solutions that address those personal needs and wants.

Seeing smiles on the faces of the people who work for me and knowing that they are enjoying working at their jobs is not just about their becoming more productive at work, but also about the genuine desire we should all have to help everyone be more positive. Here's to a more positive work environment.