I've played this combo a lot in s3 & s2, the combo is rly good, but my m8 kinda quit the game so we don't play anymore.
Anyway a game with this combo against a rogue or a warrior team consists of you keeping the rogue/warrior away from the lock and him going for whatever else there is. & don't worry about healing him, if you keep the melee away from him and sync CC-s you will be left with healing only yourself & him returning whatever hp he lost by draining/syphoning.
You dealing dmg to the rogue/warrior will make their healer come to you, which will make it easy for the lock to dot him/draing his mana & fear, so CC & dps at the same time, don't hope to do to much dps tho, u are focusing on keeping the other guy away from the lock.
By separating u can pretty easily pressure both of your opponents, just remember that your lock must keep dots up on both & occasionally fear thee dps, so you can heal up or cc if you are in a bad position.
Against lock + resto kill the pet and jsut keep the pressure up, without the pet you should be able to drink allowing you to outlast them.
Never be afraid to heal your lock's pet and concentrate on keeping your enemies away from him.
He should do well without someone on him and his fear will mostly be a great help when you are going to nuke the healer the last 35% or so.
The quickest way for a win against a healer team is for the lock to drain the healer and keep the pressure up so he can't despell the dps.
If you want shorter but not so safe gamaes, u go for the healer, CoT pet on him & max dps. Your lock will die most of the times after you kill the healer tho.
PS: Against shamys & paladins CoT is a must.
Edit: Against rogues if u can't find him with the pet buff @ the beginning, w8 for him to attack your lock and than pounce. Be sure to prevent him from dealing to much dps on your lock @ the beginning, cuz it will force you to heal & make you lose.