The first rule in performance feedback effectiveness is to make sure it happens on a continuous basis and not just once a year as an annual evaluation event. As a matter of fact, when discussing performance is considered an "event" of any kind you know you're in dangerous territory. Rather than an event, it should be part of the ongoing coaching efforts that are the responsibility of every leader. The second rule is to include both the positive and "areas of developmental opportunity" feedback. Some leaders forget or minimize the importance of providing positive reinforcement and then wonder why the good behaviors aren't repeated on a consistent basis. Remember... reinforcement means to strengthen and we certainly want to strengthen positive behaviors, right?
Even if you are doing feedback correctly and timely, chances are you are responsible for some type of formal feedback system in addition to your constant and consistent feedback. So when conducting those more formal sessions consider these tips: personally invite the employee to the meeting, provide advance notice, give the session your undivided attention (close your door and don't take telephone calls), sit next to the employee rather than behind a desk, have an agenda to be sure you stay on track and cover all items that need to be discussed.