I'm ana main myself and I'm always getting paranoid if I can't find a good wall to hug. Always ask yourself where is wall I can stick to. You should love walls. In most cases your team won't care about you. But walls, they do. Be united with walls. Become a wall!
I don't care what anyone says, he is the best coach when it comes to overwatch. He is so positive but gives points when needed, what a great guy to coach his viewers.
Thinking about what's gonna happen and shutting down plays is my favorite part about playing Ana. You know a reaper/pharah/genji/soldier has ult? Keep tabs on them during the fight and guess when they are setting up for it, save sleep dart for them, put yourself in a position to shut it down without risking your life to it, maybe even call it out to your team shortly before it happens and they will think you're a god. If you're not in a position to shut down a certain play, maybe you tell your bap what you think they'll do and to save lamp as well, or if you notice your zen has ult then let them know in the chat/voice to save it for XYZ situation if they can. Paying attention to your other support and communicating with them can be insanely helpful. I love to duo queue with a friend that plays support and we coordinate heals and playmaking abilities.
Corners are your friend as any support, but Ana and Zen specifically, because they have 0 mobility. The second key moment I was screaming for them to be on the corner of the stairs behind them and then rotate up to high ground. Those stairs are a great position to play on defense at the start of a fight. Now im just hoping ML says the same cause ive paused it to make this comment xD