There is nothing at all wrong with having a file labeled “Endings” and just selecting the most appropriate of the several concluding sentences saved from previous letters.

For the gen-ed class I teach, I also have an assortment of specific examples saved. Since the work is similar every year, I just look for a part that the student did well on, and update the specific example as appropriate.

[insert name of student] wrote a thoughtful and analytical research paper on [insert name of topic]. [Her/His] research paper is one of the few I remember from that class.* [Insert name] went to great lengths to find [quickly describe sources] to develop an original approach to the material.

Maybe that second approach is a little shady. Luckily I’ve not yet been asked to send letters to the same committee for multiple students in the same year.

* If I’m writing a letter for them, this is probably true.