At the time of performance review of an employee, feedback has to be given and that is not always positive. The feedback has to be honest, even when the employees are reluctant to hear what you have to say.  So, as a manager, how constructively you put forward the feedback during the performance review matters to an employee.

Therefore, whether you are offering good comments or criticism, keep these point in mind.

• Deliver your feedback in person: Schedule a meeting for about an hour with your employee and deliver his/her performance review. This will help in keeping it simple and straight. 
• Avoid surprises: This is a must! Provide immediate feedback if you see any issue coming up. Address the issue immediately with the employee and do not wait until things turn out to be real bad for both of you.
• Prepare your performance review in writing: Have proofs before you decide your reviews. Write down your thoughts and evaluate to avoid confusions and disputes.
• Verify before you decide: If employee performance is obtained from a third party, then you must verify it to check its accuracy before taking any action. Also, never mention the source of information or put it across intelligently as it may become a reason for conflict among the employees and result on loss of trust.
• Keep performance review professional: Talk only about the employees’ performance and appraisal during the performance review. This means, no personal talks! The discussion should only be around the feedback and future focus.
• Positive and negative-keep a balance: Firstly, acknowledge the employees positive contributions to the organization. Put forth your negative comments neatly and emphasize opportunities for improvement.
• Respect your employee: Speak to your employees with respect. Do not shout or talk with sarcasm.
• Commit only to what you can deliver: Do not make promises to your employees that you cannot fulfill. Speak accurately and mention only the possibilities.
• Don't skip reviewing your best talent: Performance review should be done to both, best and the worst employees of the organization. Do not miss talking to employees who do a good job. It motivates them to keep the good work going.
• Allow your employees to talk: Do not do all the talking. Acknowledge your employees explanation if you do not intend to change the conclusion.
• Be a guide: Give your employees some useful tips to help them improve on the areas of growth and the workplace. Feedback followed by some tips would do well for your employees.