This post was published long before the Mists of Pandara Expansion.
The tips and techniques explained here may be outdated.

Macros: Warlock

Lifetap:

/cast lifeblood
/cast life tap

My warlock is a Herbalist. Lifeblood is the innate herbalist little heal. The icon shows the lifeblood cooldown (not really necessary.. but I don’t mind). Lifeblood heals for about the amount of a life tap. So every three minutes I’m surrounded by flowers and healing a little bit.

Based on the addition of haste to Lifeblood I may be changing this.

Pet Attack:

/cast [mod:shift,pet:felhunter] Spell Lock
/stopmacro [mod:shift]
/target [help] targettarget
/petattack [target=pettarget,noexists] target
/stopmacro [target=pettarget,noexists]
/petfollow

If I held down shift …
…If I have me felhunter out, spell lock my focus.
If my target is friendly to me (ie, the tank) use my target’s target and ..
…If I have a target and my pet currently isn’t attacking anything, send my pet to attack my target.
…If I have a target and my pet -is- attacking something, call my pet back to my side.

Paraphrased: hit once to have pet attack, hit again to call pet back to you.
Hold down shift to have the pet that’s out do special things. I want to enhance the shift abilities.. but I’m still tweaking this macro.

Healthstones:

#showtooltip
/use [nomod] Demonic Healthstone
/cast [button:2] Create Healthstone
/cast [mod:alt] Ritual of Souls

Right-click to create a single healthstone. Hold down ALT to call down a cookie jar. No mod to “eat” a healthstone.

Fear:

#showtooltip
/clearfocus [target=focus,dead][target=focus,noexists]
/focus [target=focus,noexists]
/cast [target=focus] Fear

If my “focus” is dead or no longer exists, clear my focus. If I don’t have a focus, set my focus to be my target. If I have a “focus”, fear it.

Banish:

#showtooltip
/clearfocus [target=focus,dead][target=focus,noexists]
/focus [target=focus,noexists]
/cast [target=focus] Banish

Same thing as the Fear macro, only using Banish instead.

Soulstone:

#showtooltip
/use [nomod,button:1] Demonic Soulstone
/cast [mod][button:2]Create Soulstone

If I have no soulstone (and haven’t had one since I logged on) then the ? icon will show.
If I hold down a mod(shift, ctrl, alt) the icon changes to the “create soulstone” icon.
If I right click the icon it will attempt to create a soulstone. It will also create a soulstone if I hold down a mod and either right or left click the icon.
Without a mod, if I left-click and I have a soulstone it will put that soulstone on my current target, self if I have no target.

I haven’t done it.. but I could also add a trigger to “Power Aura” so it would make a sound and alert me when the ability “Create Soulstone” comes off cooldown.