Your hard work is showing in the high quality of your output. We appreciate all you do!I am immensely thankful for your mentorship and the positive impact you have had on my life and career. Your wisdom is a treasure. Learn how to write an employee appreciation letter with these templates and examples. Download the template for free (PDF or Word). To my younger self, Hey there, You did a great job! Even if no one complimented, I will. You're the best boss I've ever had. Thank goodness that hiring manager saw my potential.