Since I've seen a lot of affliction warlock discussion lately and many wrong informations I decided to write a bit on that.Bare in mind that I will be refering to a "target" as a Raid boss not ordinary mob you kill doing daily's.
Let's start with initial pull.
1. CoE
2. Dark Soul:Misery
2. Haunt
3. SB:SS
4. MG spam
5. rest of the rotation based on priorities
This is how initial pull should be done. Before anyone starts with "your dot's should be applie before haunt bla..bla..bla.." , Haunt has a TRAVEL TIME. If you are more than 20yards away from boss then your SB:SS will land BEFORE the Haunt. I hope this makes it clear. If by any chance you get trinket/lightweawe/weapon enchant proc on first MG, then it's beneficial to refresh your dot's with SB:SS if your new dots are atleast 30% stronger than old ones(how will you know this it's up to you)
Now for the "rest of the rotation" after initial pull there are some things you have to watch over.
Haunt should be casted only if you have INT/SP proc up to maximize it's damage, but if any of your dot's on target has remaining time less than 9 seconds refresh dot's first to get full uptime of dot's during Haunt. Also Haunt is ALWAYS casted if you have 4 shards so you don't loose NF proc.
Regarding dot's, all dots are refreshed on pandemic benefit if their new damage is equal or stronger than last one or earlyer than pandemic threshold if they are atleast 30% stronger than old ones. If you have strong dot's on target then you don't refresh them on pandemic but you squeeze some more MG's in and refresh them before they drop, especially Agony. If your corruption or UA drop by less than 1 second it's no big deal since last tick did more damage anyway than your new first one will do.
Regarding shards. If you are refreshing your dot's properly and Haunt on INT procs then you don't hoard your shards and save 2-3 for DS/BL. you save only 1 shard so that you can SB:SS on empowered dot's or switch target and apply fresh dot's quickly.
Execute phase. DS till you got 2 shards, then Haunt than SB:SS, then DS again and repeat. Doomguard is used either on BL or on execute. if your BL is not on execute phase than you use int pot and pop Doomguard on BL it will have more benefit.
And last thing KJC is great but bare in mind that you might get into trouble on fights like Windlord if by any chance you get 2 bombs in a row on you
Just my 2 cents
