Here is what to do:
If you have an active Icy Veins you just press GS no matter if you can flurry or not.
If you don’t have an active icy veins, then you always use flurry before GS, so you have to press frostbolt until you get a brain freeze peoc even if you have 5 icicles.
So basically
IV active → use GS whenever you can even if you cant shatter it
IV inactive → you only use GS when you can apply winter’s chill.
Listen to Zerida. Ignore Kerathus.
i don’t get it. By the time flurry will proc i might have 3-4 icicles again. Frostbolt currently does like 10k damage without wc
If you have no Flurry Proc, but you have at least 2+ targets cast the Spell. Splitting Ice makes it a damage increase. That rule is good for boss+Add or just a trash pack.
Also if they can be frozen, use Ice Nova right after the cast or even the water elementals Freeze.
They’re giving you the absolutely optimal advice. If you have IV up or are fighting more than 1 target you use GS every time it’s available no matter what. Technically if you’re only fighting 1 target it’s optimal to hold it until you get a WC proc but in my opinion it’s not worth the bother.
IV is not a permanent maintenance anymore but it still has a very high uptime so between that and the fact that you’re rarely fighting only one mob, aside from purely ST bosses, that pretty much covers most of the fight. The remaining 20% of the time or whatever it ends up being you can hold GS fora WC if you really want to but it’s barely going to make a difference.
Also, at least as far as I am concerned, the whole point of taking GS is to use it every time you can just because it looks cool and hits hard, the fact that it’s now a DPS increase too is just a side benefit for me.
He can make up his own mind. Also it would be really nice if you could get my name right when you 
talk about me. Otherwise I will have to tell Will Smith to politely ask you to keep my name out of your mouth. 
I mean he can.
Two mythic players that are actually giving advice and play the spec/content.
Or
The guy who doesn’t play mage in any content and complains all the time.
Like I don’t have any issue with you outside of you giving incorrect advice and you don’t even play the content you comment on.
fine, fine, i will not use GS without IV/wc
Common,
If you have splitting Ice and 2+ targets send it. Even if you get no crits the total damage output of that Glacial Spike using the Splitting Ice talent is a damage increase.
Always always try by hook or by crook to shatter that GS via other means like Frost Nova or Ice Nova. GS is a slow moving spell, so Ice Nova works and Frost Nova work in melee range.
2+ Targets and Splitting Ice = Cast.
Old school Frost mage tip
just a smol tangent.
The 2nd spike follows same constraints as splitting ice 2nd lance right?
Only the primary target gets the buff from winters chill?
Would it make sense to try to COC b4 every GS for 2 targets?
edit: why mages gotta be the most convoluted builder/spender/proc/debuff tracking class invented?
That’s correct, so where you can you’d be better off using Nova, Freeze or Ice Nova. Don’t forget to save one to shatter Comet Storm though.
No. You should be running the CoC capstone talent for M+ because it provides your burst and reset on CmS/Orb. Aside from it not being up for most GS, you gain far more from using it for that. If you’re talking specifically about a 2-target build then still no, because CoC won’t freeze them or apply WC.
It seems like i’m not using enough ice lances. Had another fmage in m+ dungeon, he did more dps than me and had a lot more ice lance damage, like three times more. Weird.
Yup, only the primary target you hit with Flurry has the winters chill debuff. The secondary GS victim has no debuff and if it crits that’s just a dice roll.
Let’s say your theoretical GS will shatter for 400k with that WC debuff. If you cast a GS at two targets the primary target with no crit will get hit for 200k and I think the 2nd for 180k. The total damage output is near the same for a ST WC shatter. If any part of the GS rando crits it’s a bigger dps boost.
I would save CoC with all the talents for Comet Storm and CD resets. Your better off using Frost Nova or Ice Nova to shatter that GS if possible.