I hope the magic controls are reworked with ES VI. While Bethesda has greatly improved physical combat play control in the series magic is still lagging behind. Playing a spell dependent character soon digresses to menu navigation and taping a button once for x to happen. There is no power attack, quick attack or triple strike combo that feels gratifying.
I want the same "charge" strike feature melee uses or shouts from Skyrim. One spell could easily have 3 variants.
Fireball:
Quick taps on the mouse/gamepad shoots out quick cast little fireballs
Hold the button to charge an increasing large fireball with increasing AoE
Tap+tap hold creates a cone of fire.
Summon Skeleton:
Quick taps raises a weak skeleton.
Hold the button and charge spell to summon a higher level skeleton.
Tap+tap hold summons a skeleton army.
The fire damage or skeleton(s) health depend on you skill in that school. Charged spells cost more mana and over charging leads to epic backfire where fire explodes on the player or the summoned skeleton(s) turn hostile. Animations would reflect the spell charging and the resulting spell animation.
This would make magic combat much more engaging and significantly reduces menu hoping for spell selection. Players would have better control over mana consumption or how much damage they want to do. This would also allow great hell Mary moments where players dare to super charge spells.