Hendlove is going strong for warlocks right now, so here are 2 of Hend’s favourite warlock macros.

Before the fight, set a focus target. (Try the MOTW from Ep 36!) Using the following macro will cast Havoc on that focus. If that target dies and you need to refocus and cast Havoc again, mouseover a new target and hit this. Sets as new target and casts Havoc!

#showtooltip Havoc
/focus [@mouseover,harm,nodead]
/cast [@focus,exists]Havoc

Macroexplain.com explains it like this:

If the unit your mouse is currently over is an enemy and is not dead then:
Set your focus target to the unit your mouse is currently over

If the unit saved as your focus target exists then:
Cast Havoc on the unit saved as your focus target

This gem casts your Incinerate as normal, but if you hold down SHIFT, it will cast Fire and Brimstone first. This macro can also be used for Conflagrate, Immolate, and your Curses just as effectively!

#showtooltip Incinerate
/cast [mod:shift,harm]Fire and Brimstone
/cast [mod:shift,harm]Incinerate;[harm]Incinerate

Macroexplain.com explains it like this:

If you were holding the shift key and the currently targeted unit is an enemy then:
Cast Fire and Brimstone

If you were holding the shift key and the currently targeted unit is an enemy then:
Cast Incinerate on the currently targeted unit

Else, if the currently targeted unit is an enemy then:
Cast Incinerate on the currently targeted unit

Time to blow stuff up!