I am unsure of when to use mind spike.
I've noticed that my shadow priest rotation often boils down to the following:
shadow word: pain
shadow word: death
I'm not sure where mind spike should fit, I do know that it cancels all damage over time abilities so I can't think of when to use it.
Also, is there anything I can do to improve my rotation.
Is there any difference in the approach I should take for solo, raid and dungeon play?