Consider these two excerpts from letters of recommendation:
I am of the distinct opinion that his breadth and depth of knowledge and his intellectual capacity augur such a level of grandeur that he seems almost predisposed to high achievement.
He is smart and bound to succeed.
Both sentences say essentially the same thing, but in different styles—the first with the luxuriance of Faulkner; the second with the parsimony of Hemingway.
Most recommendation letter writers fall somewhere between these two extremes, making sure that their diction and tone reflect their attitude towards the student even as they reveal their stylistic talents and traits as a writer. One can say that letters of recommendation have a common style in that they have a common purpose and share common phrasings, but the best writers aim to produce a letter that is nearly as individual as the student.
This chapter explores some of the stylistic categories we can choose from as we polish our prose while recommending students. Of course, as one composes a letter the issues discussed are naturally and tightly interwoven. The best writers express themselves in a way that is not artificial nor formulaic, but fluid and intuitive, and the best letters of reference characterize the student clearly while remaining true to the author’s style and standards. Most importantly, the goal is to write in a style that is natural both for you and for the circumstances of the letter, while ultimately uplifting and honoring the student you are recommending.
For more stylistic advice when writing letters, I recommend these sites: