1. General rule of thumb, 60s is up for every trash pull. 90s is for big pulls and every boss phase change. 120s is one up front, another after 60s, while 180s is your ohshit button.
It\\'s always better to have popped early than not to have popped at all. Don\\'t hold onto your Rampart or FoF. Pop it like you mean it. The earlier you pop, sooner it will be back up for use.
Later on once you get used to certain contents you\\'ll learn that it\\'s better to have saved some cd for scripted mechanics. These are things like Mountain Buster on Titan HM+, so those would be where your big boy cooldowns like Sentinel is popped.

3. Tab to see their enmity meter on individual party members.

Use Fast Blade or equivalent on your primary target to \\'prime\\' it, get Savage Blade/Skull Sunder on the next, RoH/BB on the other. Prime it again, SB/SS the next and so on.