With a Warlock comes many abilities to use to do massive damage and many cool things you may never have thought of doing. And spells are at their most effective point when done with the right combination of other spells, such as debuffs, damage over time spells, area of effect spells, and healing (or in the Warlock's case, healing and damaging) spells. This article will start out with some spells and descriptions, then it will show a way to combine them with some other spells. Then it will repeat that process after all combinations are covered. It may also cover a group of spells (Such as curses) instead of each individual spell to make it easier to read the article so you aren't reading similar looking sections.
Tactic One[]
Drain Life[]
Main article: 
[Drain Life]
Drain life is a spell that will drain a small portion of your enemy's health and heal you with about the same amount every few seconds. What makes it so effective is that fact that not only does it damage your your enemy, it heals you at the same time!
Curses[]
Curses are a group of debuffs that act as damage over time spells for the Warlock class. They are highly effective at causing your enemies to lose health when you may be low on mana, especially since they don't take too much mana either. It's also good to match with direct damage abilities.
Searing Pain[]
Main article: 
[Searing Pain]
Searing pain is decent at damaging enemies and has a very low cast time. Which, with mixing all that in, can create a pretty good spell to use when you have your enemy down.
Soul Fire[]
Main Article: 
[Soul Fire]
A powerful spell with a long casting time. It is excellent for causing massive damage to attempt to keep your enemy from having a chance at all in combat. It is a spell that will make sure that you have the upper hand in fights.
How to use the spells effectively[]
When you start up the battle, open up with as many damage over time spells and debuffs as possible. Then, cast Soul Fire on the enemy once or twice depending on the amount of health the enemy has after the first cast. After that, you will want to case Searing Pain a few times while maybe casting Shadow Bolt if you prefer. And, while casting your direct damage spell, you will want to cast any debuffs that are low on time if the enemy still has quite a bit of health left. Also, use Drain Life to keep yourself healed.
Fun effects with the different spells[]
Cool mount effect to do with a Blood Elf Warlock[]
Before casting the 
[Summon Felsteed] or 
[Summon Dreadsteed] spell, cast the 
[Arcane Torrent] spell.