Instructions
Place all the beneficial spells that you have -- such as Power Word: Fortitude, Vampiric Embrace and Inner Fire -- on yourself.
Cast your Shadowform ability to improve your own spells and to reduce the damage you will take from enemy attacks.
Pick targets that are the maximum possible distance from you so that you have as much time as possible to cast your spells before your target can even start dealing damage to you.
Place your damage-over-time spells on the target, starting with Vampiric Touch, if you have it, and then Shadow Word: Pain. Recast these every time they wear off the target.
Cast your Mind Blast spell on the target to inflict a solid amount of damage instantly. This will also give you a replenishment effect if Vampiric Touch is on the target, restoring your mana over time. Recast Mind Blast every time it comes off cooldown.
Cast your Mind Flay ability to deal channeled damage and slow your target if they have not yet reached you.
Cast the Shadow Word: Death spell when your target is below 25 percent health to inflict a heavy burst of damage.