When my oldest boys were growing up, I decided to have every teacher and important person in their life write them a letter. I included all teachers, coaches, pastors, and anyone else who was influential in there life. Many of the people I asked never got around to it, but I did get quite a few through the years and saved them for when they graduated. It was a nice way for them to read what others said to them and to look back on memories of teachers.
Although I love the idea of handwritten letters, I heard recently about a dad who created an email account when his daughter was a baby. He sent an email to her with each step taken and every important milestone in her life, but kept it a secret. When she was older he told her about the account and she was able to read every letter he had written to her.
Both of these are awesome ways to share with your kids the words you were feeling and how others thought of them growing up. Even if they were too young at the time, or you didn’t share out loud, they will have a permanent record to keep.