Make sure you have around 30 minutes of something to do when you're not on your warlock.
Blizzard has made it so that when you log out, your cooldowns go down, but your buffs and debuffs stay up. This could be used with many other things, like Pally bubble, ect..
Lets say you're getting ready to raid, and you want to put a soulstone on yourself. Get your soulshard, give yourself a soulstone, then log out. In 30 minutes, when your raid starts, you'll still have your soulstone but your cooldown on your next one will be gone.
That way, you can have a soulstone on both you and a fellow Priest (or other class) when the raid starts. Enjoy <3
P.S. - 5 inches of snow now, day off tommorow ;p