There will always be many different opinions about how we should play technically and artistically. One teacher can tell you to play in a certain way while another will tell you the exact opposite!. On top of that,if you search the web, you'll find an unlimited amount of ideas not always going in the same direction. So how do you sort out all this input? Who's right?
You can trust one teacher or another but the person you should trust the most at the end of the day is YOURSELF.
You are the one who's playing and you're in the best position to see if what you're taught actually works. You have every right to seek as many opinions as you want on a specific topic and choose the one that YOU find the best. It's YOUR playing and YOUR life. You're the boss.
Before you ask a teacher what he/she thinks, you can ask yourself what do YOU think and how do you feel about it. At the end you're the one performing so your opinion should matter. Make your own experiments. Try things for yourself and be your own teacher. Some things you'll try will work and some won't. That's okay. You don't need a 100% success rate. You'll always make more progress if you're proactive about your playing than if you just passively wait for someone else to show you the way.
As long as you regularly get feed back from a teacher who has more life and playing experience than you and can make you see and hear things you wouldn't notice otherwise and show you techniques and ideas, you can make your own decisions and be in control of your own playing.
I am associate principal horn of the Singapore Symphony Orchestra and the author of the progressive methods. I'm happy to share my experience as a horn player and teacher with you.