Interface
With Midnight pre-patch, a lot of the addons we’re used to having will no longer work in the way we’re used to or not at all in some cases. What the “meta” addons will be are very much still in debate so we will have to see in the following months.
Lucky for us the Blizzard default UI is getting better every patch so you can make a very sufficient UI by just messing around in edit mode and configuring their Cooldown Manager to show what you find relevant.
However, it’s still important to have a good way of tracking your soul shards as well as Immolate/Wither on your nameplates, especially with good boss frames being gone. For this I recommend Plater.
Macros
Some useful macros for Destruction Warlocks are cursor location macros which cast the spell at the location your cursor is when you press the spell.
Summon Infernal Macro
#showtooltip
/cast [@cursor] Summon Infernal
Shadowfury Macro
#showtooltip
/cast [@cursor] Shadowfury
Cataclysm Cursor Macro
#showtooltip
/cast [@cursor] Cataclysm
Rain of Fire Cursor Macro
#showtooltip
/cast [@cursor] Rain of Fire
Also, some useful macros you can use are mouseover macros.
Havoc Mouseover Macro
#showtooltip Havoc
/cast [mouseover,harm] Havoc; [harm] Havoc
Havoc Focus Macro
#showtooltip Havoc
/cast [target=focus] Havoc
Soulstone Mouseover Macro
#showtooltip
/use [target=mouseover] Soulstone
Spell Lock Focus Macro
#showtooltip
/cast [target=focus] Spell Lock
Curse of Tongues Mouseover Macro
#showtooltip
/cast [target=mouseover] Curse of Tongues
Curse of Exhaustion Mouseover Macro
#showtooltip
/cast [target=mouseover] Curse of Exhaustion