Depends really.. Are you talking about single mobs in the world or in a dungeon? Dungeon mobs have higher health, so it's usually OK to go through the long rotation, mobs out in the world are pretty weak though, so you can burst them down with just the TTT.

I've been multi-dotting mobs in dungeons, for that you just HT-I-D-C-Ph mob 1, I-D-C-Ph mob 2, HT-I-D-C-Ph mob 3, then go back and TTT to finish them off, HT'ing as needed.

If there are 4 or more mobs use AoE. Ring of Thorns is lower potency but longer lasting (less TP usage), Doom Spike is amazing with IR and B4B but will drain TP quickly and has some positional considerations because it's a straight line AoE. My usual AoE rotation is HT-(IR)-RoT-(B4B)- RoT spam/DS Spam. Reapply HT as needed and use Invigorate at around 300 TP.