When someone pays you the ultimate compliment of asking for you to influence who they are becoming, handle them gently. Strive to catch them doing things well. Give feedback often. Correct in private and praise in public. Make it fun.
Charts are a great way to monitor progress.
When you use a chart that is posted in a conspicuous place it acts as a motivator. It will show you where you have been, where you are right now and where you are going. Benchmark the chart with three reference lines. First chart expected results. Then add a different line to indicate heroic effort and a red line to indicate the absolutely unacceptable level of performance.