Perform a kindness, but do it anonymously.
There is nothing so uplifting as being the recipient of a kind deed. And when that action is done anonymously, the kindness is taken to another level because the anonymity itself becomes a gift -- a way of saying: This is for you. There is no need to say thanks, or feel beholden. Take this, I give it freely.
Twenty years I was teaching high school in a rough neighborhood when I had to be present at a parent conference in the principal's office. It wasn't one of my students, but I had witnessed an incident and had to be there. The entire situation was ugly, the parents were hateful, and when the conference was over I returned to my classroom in tears.
The next morning I arrived early to school and found a beautiful flower arrangement on my desk. The vase was ceramic, made to look like a stack of books, which made it the most perfect gift for an English/Spanish teacher.
Best of all, nestled among the flowers was a lovely, encouraging note telling me how I was making a difference in the lives of my students. The note was unsigned.