My list of donts for newer players:

Don't do any healing during a pull if possible, wait til the first flash/overpower.
If you don't understand when fluid aura is bad, take it off your bar.
Dont just stand there, always be casting; if you don't need to cast a heal, deal dmg.
Don't 'heavy' mobs during a pull (miasma/stone I) in your case.
Repose... Don't be that guy.
Limit break... Or that guy.

My list of do's for new players:
Use interactable like keys, doors, etc.
Remember to use your cooldowns.
Run to me if you've picked up aggro.