Counter Class Knowledge
Read up on arenajunkies and also – practice will really help.
Depending on your type of class, you’ll want to write down a list of counter classes that can counter you. In my case as a lock or a DK — I care about who can dispel my DOTs. For example, on my warlock, I need to know which healers can cleanse magic. On my DK, I need to know who can cleanse diseases (all healers but a DRUID). Depending on what class you are, make a list, and know which ones you need to be extra careful that they are canceling out all your dps.
If you have never played on the test server – do this. Make sure you know the main 6-7 abilities of every class.
Make sure you know how to play every class well. There should be no ability that you see that you cannot call out. Use “Juked” to test your knowledge. It can show you 68 abilities to know intimately.