-PVE :

On most fights try to pre-buff yourself with Flames of Oblivion before you engage:

Flames of Oblivion > LA > Rearming Trap > LA > Eruption > LA > Elemental Blockade > Weapon Swap >
LA > Burning Embers > LA > Engulfing Flames > LA > Lava Whip x5 (With Light Attack) > Weapon Swap >
LA > Elemental Blockade > Weapon Swap >
Burning Embers > LA > Engulfing Flames > LA > 2x Lava Whip (With LA) > Weapon Swap >
Restart

In case you use Channeled Acceleration, make sure to use it when the boss is moving to another position, so you can focus on your rotation while the boss is stationary.

LA = Light Attack

-PVP :
Mundus Stone: The Atronach (Increased Magicka Recovery).
Championpoints:
The Ritual
16 Thaumaturge
The Atronach
56 Master-at-Arms, 48 Shattering Blows
The Apprentice
37 Elemental Expert, 31 Elfborn, 55 Spell Erosion, 27 Blessed
The Shadow
58 Tumbling, 50 Shadow Ward
The Lover
75 Arcanist
The Tower
75 Warlord, 11 Sprinter, 1 Siphoner
The Lord
37 Quick Recovery
The Lady
43 Hardy, 43 Elemental Defender, 37 Thick Skinned
The Steed
52 Ironclad, 58 Resistant
FIRE STAFF RESTO STAFF
Slot 1: Burning Embers Slot 1: Reflective Plate
Slot 2: Fossilize Slot 2: Mutagen
Slot 3: Flame Lash Slot 3: Ward Ally
Slot 4: Elemental Drain Slot 4: Volatile Armor
Slot 5: Empowering Chains Slot 5: Cauterize
Ultimate: Ferocious Leap/ Temporal Guard Ultimate: Life Giver

Source and more detail: https://alcasthq.com/eso-magicka-dragonknight-burst-build-pvp/