Take Notes 

• After every difficult win or loss, try to learn from the experience. Take notes. I keep a note pad on my desk next to where I play.
• Aim to recreate game winning moves. When you have a big win against a nasty team, write down notes as to how you accomplished it.
• Same thing goes for unbearable losses. Nothing is worse than spending 20 minutes on a loss, and learn nothing from it. Who beat your ass? A rogue? Write it down. Start dueling rogues. Learn all their abilities by heart.
• Aim to take away 1 important new learning from every difficult win or loss. Write it down so next time you suit up, you think about how to beat that which plagues you.
• For me, my pleasure in the game comes more from learning than from the actual wins. As long as I know I am learning something new every day in wow, then I continue to enjoy the game. If you get stuck at 1400 and beat your head against the wall, you are likely not trying enough to learn from your wins and losses.

Abilities 

• Re-read all your abilities once a week to refresh for any small edges you may have forgotten about.
• Discuss them with other ppl that play your class.
• Re-read them after every patch.
• Know which ones are magic, not magic, dispellable, etc.
• know which spells come off when the gates are opened.
• know which abilities are off the GCD and combine them all into one macro for OCD or DCD powerups.

Coaching 

• Find someone on the server that plays your class/spec at 2K+ level and ask for help. 9/10 people like to share advice and help out. Ask that person to sit in skype with your team and listen to your communication.
• Also, you can fraps your movies and post them to youtube and ask your coaches to review your play. If you are lucky, your “coach” will have a free 2s team and is focusing on 2200+ in 3s, and can actually play with you.
• Do Skype Screen Shares with them, so they can see your mistakes, and correct them when you play WSG or Arena. Then do the same with them, and listen to how they think things through.