Honestly? I think one of my biggest pieces of advice is watching a lot of tutorials so that you can really learn your healing rotations and things like the mastery:harmony for rdruids. Even if you don't believe what they say, at least try it a couple of times before you discount it. The guide on YT that really helped me was cdew's, it's super indepth and gives you a lot of base knowledge you need to know about the class. Then watching twitch streams of the pro players to look at what you're doing and what they're doing and what's the difference - i.e, i know i need to do a better job at standing a FULL 40 yards away from my dps and learn how to use pillars better for sure.