I teach large-lecture classes and students often report feeling lost in class and not being able to interact with the instructor. The transition from high school to college can be challenging on its own, but it can be even more confusing when students lose their connection with instructors. So much of my time is spent on the median student and making sure students at the bottom of the distribution get the help they need to pass. Often, I found myself not worrying about the top students because they were "doing fine without me." That changed when I started to realize that the top students want to be challenge, rewarded, and noticed. We often just assume that the top students are motivated by their grades, but they may need more.
I started writing personalized thank you cards to students who score top grades on my exams. The usual cutoff is a 95% or better, but it really depends on how many students are in the top end of the distribution. I also write thank you cards after the second exams to students who showed major improvement between their scores. Again, these are students who are often lost in the middle and are often looked at as having gotten it on their own.