Here is a simple list of all my macros that I currently use in World of Warcraft: Classic.

Generic Classic Macros

Clear Action Bar Macro

This macro will remove any Spells and Macros on your action bars, use with caution.

/run for i = 1,120 do PickupAction(i) ClearCursor() end
Upper Trinket Macro

This macro will let you use your upper slot trinket.

#showtooltip
/use 13
Lower Trinket Macro

This macro will let you use your lower slot trinket.

#showtooltip
/use 14

Warlock Classic Macros

Dain Life, Drain Mana & Health Funnel Macro

Without pressing any key modifier, this macro will Drain Life your current target. While pressing the alt modifier it will Drain Mana your current target. While pressing the shift modifier it will Health Funnel your pet.

#showtooltip
/cast [mod:alt] Drain Mana; [mod:shift] Health Funnel; Drain Life
Drain Soul Macro

This macro will automatically delete the Soul Shard that is in your fourth bag, in the bottom right corner. This macro will only work if you have a Soul Shard bag equiped in your fourth slot bag.

#showtooltip
/cast Drain Soul(Rank 1)
/run PickupContainerItem(4,GetContainerNumSlots(4)) DeleteCursorItem()
Rain of Fire & Hellfire

Without pressing any key modifier, this macro will cast Hellfire. While pressing the alt modifier it cast Rain of Fire at your cursor location.

#showtooltip
/cast [mod:alt, @cursor] Rain of Fire; Hellfire
Pet Ability 1

This macro will cast your pet main utility ability depending on which pet is currently summoned. Sacrifice for Voidwalker, Spell Lock for Fel Hunter, Secudtion for Succubus and Fire Shield for Imp.

#showtooltip
/cast [pet:voidwalker] Sacrifice; [pet:felhunter] Spell Lock; [pet:succubus] Seduction; [pet:imp] Fire Shield
Pet Ability 2

This macro will cast your pet second utility ability depending on which pet is currently summoned. Consume Shadows for Void Walker, Devour Magic for Felhunter. While pressing the alt modifier it will Devour Magic your mouse over target.

#showtooltip
/cast [pet:voidwalker] Consume Shadows
/cast [pet:felhunter, mod:alt, @mouseover] Devour Magic; [pet:felhunter] Devour Magic