How do you become a better teacher? Beg, borrow, and steal. Watch your colleagues, go to veteran teachers, ask them what works for them. Really, veteran teachers on your campus are the best source of information and support that you could possibly have. They have the same students as you, they work in the same school under the same policies as you. They know what works. And finding out from them and using them as a resource is the number one way to become a better teacher. Let them help you. Ask for support.
Also, videotape yourself or have your trusted veteran colleague come in and observe you teach and give you feedback on what is happening. Using videotape if somebody can't come in to your classroom is really excellent, not only because you can sit and watch that video together, and then go over what you thought went well and what didn't and they can give you advice, but also, if you don't know anybody on the campus, you don't have a trusted colleague yet, you can look at that video. And you will see things that you did not notice while you were in your class, distracted by your 35 students.
If I was to do just one thing to help a teacher improve, it would be videotape them and go over the video with them, so that we could get right to the heart of what is the number one thing that would help in that classroom, in that situation, with that person.