Glossary, Mechanics, and DPS Cycles

Before we begin discussing how to properly understand and play PvE Frost; we will start with a Glossary of short-hand notations for relevant spells; as well as Fingers of Frost and Brain Freeze Proc States. Do your best to memorize them; they will be used exclusively from here on.

PvE Frost Glossary of Terms
Important PvE Frost Mechanics
Fingers of Frost - Gives your offensive Chill effects a 20% chance to grant you the Fingers of Frost Effect, which causes your next Ice Lances or Deep Freeze spell to act as if the target were frozen. Ice Lance damage is increased by 25% while under this effect. Maximum of 2 charges. Lasts 15 seconds. Allows the use of Deep Freeze on non-frozen targets.

Spells that proc Fingers of Frost include:
Frostfire Bolt(Glyphed and Unglyphed)
Frostfire Orb(with 2/2 talent points invested)
Blizzard(with 1/2 OR 2/2 talent points invested)
Pet Freeze(with the talent Improved Freeze)
Brain Freeze - Gives your offensive Chill effects a 15% chance to grant the Brain Freeze effect, causing your next Fireball or Frostfire Bolt to be instant cast and cost no mana. When FFB is instant, it can benefit from Fingers of Frost*.  Brain Freeze cannot triggered by Frostfire Bolt.

*This effectively means:
Casted FFB(rarely used) = No Shatter bonus, No Mastery bonus
Instant FFB(occasionally used) = No Shatter bonus, No Mastery bonus
Instant FFB w/ FoF active = Shatter critical chance applied, Mastery bonus applied

Spells that proc Brain Freeze include:
Frostfire Orb(with 2/2 talent points invested)
Blizzard(with 1/2 OR 2/2 talent points invested)

PvE Frost Cooldown Cycling Discussion(Icy Veins + FFO)
When compared to Arcane or Fire specializations, Frost has a large number of activated cooldowns to keep track of and manage.  There is some variation on how a player can handle these cooldowns based on personal preference, and specific encounters. There are currently TWO established methods for cooldown usage. These are appropriately named Compressed Cycle and Staggered Cycle for reasons you will understand in a moment.  Each has it's own benefits and applications so it is important to know, understand, and use BOTH methods depending on the circumstance. Currently, there only a few vocal PvE Frost Mages sharing their experiences and parses but from the data presented, both cycles yield similar DPS output over the course of an encounter.
Compressed Cycle
A compressed cycle will be using Icy Veins and Frostfire Orb simultaneously.  The benefit of this method revolves around the mechanics of 2/2 talented Frostfire Orb. When active, FFO has the potential to proc BF and FoF at a minimum rate of 1 charge per second. Factoring in a players haste rating, procs can occur even faster.
In either scenario, we have significant problem. FFO is proccing FoF/BFs faster than the GCD allows us to discharge them, representing a loss in DPS.  A compressed cycle is using the benefit of a lowered GCD and Frostbolt cast times under Icy Veins to reduce the chance that an FoF/BF overwrite will occur.

The downside to this method is that there is a lull or "dead period" of around 1 minute after every IV+FFO pop where you don't have a DPS cooldown to activate and are completely reliant on base cast time Frostbolts and Pet Freeze for procs.

Staggered Cycle
A staggered cycle will be using Icy Veins after Frostfire Orb fades.  The rationale behind this method is that any FoF/BF charges overwritten during FFO while foregoing IV (due to cast time or GCD constraints) will even out due to the reduced cast time of Frostbolt in the IV period that follows (hence a comparable number of usable FoF/BF procs over the same time period).

The lull or "dead period" when compared to a Compressed Cycle is reduced from 1 minute to 30 seconds. The downside to this method is a reduction in "Spike DPS", and having to delay effective Cold Snap usage.

Cold Snap Usage
C-Snap usage depends entirely on which cycle you begin with and total encounter fight time. Obviously, you will want to use C-Snap when Icy Veins, FFO, and Deep Freeze have all recently been used for maximum effectiveness. Due to the very existence of C-Snap, it is important to note that neither cycle is mutually exclusive and it is advantageous in most instances to use a mix of BOTH in any given fight.

For total encounter fight times <7 minutes, you will want to use a compressed cycle opener, and C-Snap after the first set of IV+FFO+2nd DF (30 second mark) uses to ensure you have a 2nd C-Snap available at the very end of the fight.

For total encounter fight times >8:30 minutes, you will want to use a staggered cycle opener and C-Snap after FFO and IV have been used a 2nd time and Deep Freeze has been used for the 5th time.(2 minute, 30 second mark). This seems counter-intuitive, but delaying C-Snap for this long increases the likelihood that your heavy damage periods are aligned with Proc Trinket ICD's and On-Use trinket cooldowns.

...sufficiently confused yet? The following graphic should help you make sense of all this.

(Under construction!)