The following is a 4-step process to deliver a constructive feedback.

• Prepare Scene

• Timing. Do it closer to the event so it can be easily recalled. 
• Place. Constructive feedback should be given in private, while praise has its maximum effect when done in public. 
• Give Specific Feedback
  • Think of your main goal which is to increase productivity and to resolve issues. This helps you to avoid getting emotional.
  • State at least two truisms. These are facts that you both agree to be true, which helps to set the scene.
  • Be specific about the problem. Do not use general words such as always, never, everyone and so on. 
  • Try not to sound as if you are threatening your team members. Threatening attitudes have a negative effect and reduces productivity.
• Pause
  • Ask questions and wait for answers. 
  • Let him to come up with a description of the problem himself.
  • Ask open questions (see Questioning Techniques) to get meaningful responses.
• Work on Solution
  • It is not your job to come up with the solution. They can understand the solution with a bit of help from you through questioning.
  • Since they make the solution, they will own it as well. It is more likely for them to follow up with the solution if they present it themselves in their own words.
  • Since you are listening to their solution, you can make sure they have understood the problem.
  • Use let us and do to deliver your request.