Use macros + Gateway religiously.
It took awhile to get used to using the gateway off of CD. Just take the encounter step by step. Phase 1, Phase 2, Phase 3, repeat. Don't worry about the felhunter phase when you're dealing with Phase 1.
ProGlyphs + Talents and abilities
Unbinding Will [Talent]
Gateway Attunement [Glyph] ** this one though is just for derp moments if your forget to click.
Fight from Affliction PoV
note: I had just transferred to a new server right after I got the quest so my ui was kinda messy.