1. Lead with Behavior. Don't let emotions get in the way. Jot down a plan, that way, it makes it easy to stay on topic. Make a list of the problems you would like to discuss and then explain how the employee's behavior directly affects the company and productivity. Rather than telling the employee's what they should stop doing suggest to them what you expect of them.
2. Eliminate Judgment. When having these conversations you should put your judgment aside and focus attention on the performance issue. If you start the discussion by accusing the employee the only thing that will end up happening is the employee getting defensive.
3. Ask Solution-Oriented Questions. The savviest leaders allow employees to come up with their own solutions. When employees are given the opportunity to create their own ideas they feel like they play an important role. If there is something that you don't agree on you will be able to discuss the reasons why and be able to find a happy medium.
4. Give Them Ownership. Through these conversations, you want to help the employee feel a sense of ownership over their performance and ability to change. Putting the ball in their court gives them a better sense of control and responsibility. Asking questions and receiving feedback is the best way to come to this conclusion. Managers, as promoters for change, can help enable this by continually making expectations and goals clear and consistent and striking up these performance conversations regularly.