Quote Originally Posted by Yimiko View Post
Fourth, you use your defensives in combat, not before going into combat. If you pop a bunch of them off and then rush in, you are generally just wasting time out of them and getting less out of them. Best way to use defensives is to weave them between GCDs, often at the start of a pull. Some pair well, and you can double those up(arm's length + rampart can be really nice in a big pull), but otherwise it's best to spread them out one at a time so you can get more mitigation over time.
worth adding here or making a separate point, when tanks get access to their invulns, treat them as normal cooldowns, using them as emergency cooldowns it's already too late in a lot of cases.