Why am I talking about teacher recommendations now?
By the end of Junior year, you should have a good idea of which teachers you will ask for your college recommendations. I advise students to make those requests at the end of Junior year. Most colleges ask for at least one; many ask for two. More than that is typically optional. Unless otherwise specified, the three priorities when choosing teachers to write recommendations are:
Someone who knows you well and can say positive things about your character other than the obvious (you are a good student who is conscientious and works hard is obvious)
Someone who taught you recently. Sophomore year is not as recent as Junior year and Senior year teachers likely will not have spent enough time with you. So, this is the year!
Teachers from core academic subjects (History, English, Science, Math). You should target one from English/History/Social Studies and one from Math/Science. Other subject teachers might be relevant depending on programs to which you are applying.
How does a teacher get to know you apart from all the other students in their class? If you haven’t already, NOW is the time to think about taking an active role in your education, to perhaps take a lead role on group projects, go to office hours to ask questions or get feedback on a paper, and sit in the front of the class. Teachers know when you aren’t being genuine; therefore, do these things in the genuine pursuit of knowledge and learning. Don’t just show up – engage!