The learner must perceive a need–if the learner already thinks they know it all, then they won’t be ready to learn from you. Let them create their own need by failing a couple of times first.
Feedback can be either written or verbal. I use both. Usually a mix of clear concise written feedback incorporating comments about where they can improve along with areas they should continue works best.
Scoring each area on a scale also works in clarifying the feedback. Feedback has to be accurate showing you observed them closely and made good written and mental notes.
Describe what happened but don’t make general comments when giving feedback. It is much better to say exactly what was done well, or what could be improved upon. By providing specific examples, the learner knows exactly where to focus their efforts in order to improve.
As a general rule, people enjoy getting positive feedback and don’t like hearing too much negative feedback. Providing positive feedback shows support in their efforts and fosters more open learning. Often when you address someone’s strengths, the flip side is a weakness that they notice on their own. Start your feedback with positive statements. As I like to say, “two strokes for one poke,” meaning for each negative they have to work on, we give them two positives they should maintain.
Keep in mind that the message delivered isn’t always the message received. Check to ensure that your perceptions are accurate with them also using the aforementioned methods. Not only does it ensure you are both on the same page, but it also helps to ensure the feedback sinks in. When the learner states they agree with your feedback, you know they’ve absorbed it. If the learner disagrees, or is confused with any of the feedback, discuss it until they are clear.