Do not keep your criticism to the performance evaluation which takes place only once a year. Since the purpose of criticism is employee development, provide your feedback continuously, preferably immediately. The best time to express criticism is when an employee is making progress but still has room for improvement.
Ask questions
The purpose of providing critical feedback is not to state that an employee is doing things wrong and tell him how to do right according to you. Your goal should be to find the causes of problems and that is what questions will help you with. Ask why the employee did what he did and what he himself thinks he could do better.
Listen and learn
Listen to what the criticized employee says carefully so that you really understand his thinking and actions. When you understand his motives, you will better know how to help him to change the behaviour.
Criticize behaviour
You have certainly heard this basic rule of criticism many times but it would not hurt to repeat it agin. Never criticize an employee as a person, only a specific behaviour of his.
-Kk-