I transitioned in the middle of high school, so jr and senior year I went through this constantly.
People who knew me before were confused when the teacher corrected my name on the attendance sheets, and people who didn't know me were confused when they didn't correct my name on the sheets. There was no winning.
Jr year in my english class, this girl who just happened to have the same birth name as me, decided one day towards the end of the year, to start correcting everyone by telling them that my name was so-and-so. The problem making students sat on one side of the room, which is where she sat, and the good students sat on the other, which is where I was sitting. Luckly this guy called me by my birth name, so I corrected him, and he was cool. Although he made numerous sex change joke through out the coarse of two years, I had the same teacher for two years.
The most significant time was when I didn't raise my hand when my birth name was called, so I went up afterwards to tell him that I go by Braden, but my birth name is so-and-so. We had a sub the entire week, so bless his heart, wrote a note to the rest of the subs who were covering the teacher to let them know about the change so it would not be a burden to me.
But there were times when the subs got really pissy towards me when I refused to raise my hand and went up to them later. This one lady pretty much blew up in my face. I still to this day don't understand why. Other times, other students who knew me would point me out, this happened in that same freshman class, being that they were very immature, it did not go over so well. Guys who would talk to me before, suddenly would ignore me. But it didn't really matter, I ignored them to begin with since they thought I was a freshman who skipped a couple of grades, when in reality I was a senior.