How you play
First of all, its important to
know your limits, and your durations.
namely the spell called 'Stifle'
I know exactly how many spells i can cast before it runs out.
i can stifle blast my enemy to hell, and cast frostnova with 2seconds to start running before it ends.
(this information = against a fighter. otherclasses have never really bothered me. so you guys can figure out other classes for your selfs. or a pro mage can fill in what i missed out.
'Stifle' is your main weapon, use it every chance you get..
When to use fear
Now i admitt, i can be wrong about this.. i use fear mainly to save myself incase i havent managed to get far enough, when stifle runs out. sometimes i get enemy to critical hp and take a gamble to try and kill them. which sometimes i loose on. when this happens, i need time to cooldown and mount the next barrage of spells.
i have heard of other ideas that sound equally as viable e.g. cc fear etc. you will all find your own stifle.
Chaincast
Now this to me is my special weapon. Nowdays a fighter is too smart to stand in inferno & frost nova.. or if you try to lay double inferno, the fighter starts to run because they know there limitations.
i wont lie, its only if a fighter is standing in double inferno that a mage outdamages him. however there are ways around this.. its a funny little combo i figured out that completely takes the enemy by suprise. and the best part is.. you dont even need to cast inferno to do it.
you can do it with frostnova aswell

fighters dont pay attendsion to Frostnova but seem to be more alert when they see inferno.
Anyways, here is what i do.
the right time to use this combo is when the fighter is on stifle. and his devastate fails to stun all together.
combo: Frostnova OR inferno. CC Magic Eruption/burst (cant remember what its called on OS fiesta).
yes am not lying, magic burst. when you do this combo its prettymuch = to a fighter doing stack damage.
Fighter takes the damage of 3 powerful spells in under 2 seconds, leaving them pretty confused as towards what just happened.
Dont give them time to get there heads around it. blast them with fireball and magic blast combo. stone heals/pots honestly will not be fast enough.
AOE'S
This is my wall. i use it defensively. i try as manytimes as i can, to lay frostnova and inferno at my feet before blasting the fighter.
MAKE SURE YOU DO NOT TRY TO LAY AND AOE WHEN STUNNED.. i dunno if this happens on OS.. but if you do it when stunned on EU fiesta.. you end up stuck for like 12seconds. unable to move at all. by the time you get out of it. fighter is just about ready to devastate again.
Distance Gaining Spells
The combonation is simple and the heading shows its purpose.
IB,LB/LBst. if more distance is needed. use spells such as spell steal. and that manage killing one (cant remember name)
It is rare that i use any of those 3 spells to be honest, after being able to combo magic blast& fireball. the rest of the spells seemed pretty uneeded.
Ill leave others to explain styles of play in more detail.