You want your employees' creativity to be like free-range chicken: controlled, yet free to roam around.

At the same time, you need to be careful when it comes to creativity, or else you can inadvertently crush it. "There are a lot of myths and misconceptions about where creativity comes from and how to nurture and grow it in a team. As a result, even well-meaning leaders can end up killing the creativity of a team when they need it most," writes David Burkus, the author of The Myths of Creativity: The Truth About How Innovative Companies and People Generate Great Ideas, in Harvard Business Review.

Burkus says there are common things leaders do while trying to foster creativity that, in reality, are "accidental creativity killers." Here are three you need to avoid:

1. Brainstorm overkill

There is such a thing as too much brainstorming. "Brainstorming as commonly practiced represents just one step in the large creative process, a step often referred to as divergent thinking," Burkus says. He explains that if all you're doing is writing everyone's ideas down as they shout them out, you're not doing it right.

"Before divergent thinking can have any benefit, your team needs to have thoroughly researched the problem and be sure that their brainstorming answers the right question," he writes. "Afterward, divergent thinking should be followed up with convergent thinking, where ideas are combined and sorted out to find the few answers that might be the best fit so that they can be prototyped, tested, and refined." 

2. Hosting a friendly discussion

If your team is cohesive and friendly, that might actually be a bad thing. Interestingly, "when it comes to creativity, the best teams fight a little (or even a lot)," Burkus writes. "Structured, task-oriented conflict can be a signal that new ideas are being submitted to the group and tested. If your team always agrees, that might suggest that people are self-censoring their ideas, or worse, not generating any new ideas at all."

Forget the practice of letting every idea an employee says go up on a whiteboard. To improve the quality of ideas, each should be debated vigorously before anything is written down. "As a leader, it may seem like your job is to break up fights, but don't be afraid to act as a referee instead--allowing the fight over ideas to unfold, but making sure it stays fair and doesn't get personal," he writes.

3. Shooting down ideas before they're tested

Research has found that most leaders are extremely bad judges of new, innovative ideas. Burkus says that if ideas are judged before they are tested, it can negatively impact creativity. "We tend to favor ideas that reinforce the status quo, and managers often tend to reject the ideas customers say they want," he writes. "Compounding the issue is that, once an individual or team presents the idea and is met with rejection, the likelihood of them continuing to 'think outside the box' is diminished."

This process of getting ideas greenlit by the company hierarchy before implementing them results in the same old ideas getting play and the more creative ideas getting shot down. Burkus says you should test ideas first and postpone judgment until you know if your customers like them or not. "Whether it's by giving everyone permission to prototype, like Adobe's Kickbox, or by selling the product before it actually exists, focus on getting real results to demonstrate proof-of-concept before new ideas need to be pitched," he writes.