i mean you would have better dps output while casting FL and CS on cool down rather than FL alone
You always cast your FL when you can. And juggle between death field, crushing darkness, chain lightning, chain shock, afflic. Be watchful with your cool downs. You FL all the way but when these cool downs are up you have to unload them.
Wrath seems to proc enough, it's usually up enough for me to unload instant CD/CL's whenever I need. I only ever use Shock as a finisher in PVP and I tend to use DF before I use CD and Affli
My rotation is FL spam(Wrath Proc)>DF>CD>Affli>FL spam(Wrath proc)>CL and then do that over and over, the CD's tend to line up perfectly and wrath procs aren't really wasted at all.
EDIT: Just saying, the Death Mark proc makes it so that CD and Affli hit 20% harder, so using Death Field before either of those skills makes the most sense to me.