Hi Just Some Handy tips that i have found save time in raid encounters.
The Current Encounters where i have found teleport most useful for increasing dps time are :
maexxna - if you have been cocooned and need to get back within range of the boss quickly.
Grobbulus - place the portal before you run into a corner to place the cloud an you can then teleport back without taking more damage than necessary.
Thaddius - really handy during the positive negetive phases , simply put a portal down once you get your first side , then after you are asked to change back to that side simply teleport saving you time.
Heigan the unclean - place it at the first section and it becomes a handy tool for getting ready quickly for teleport also gives you time during the dance to pull off a haunt or Ua or immolate.
Loathweb - place a portal behind the tank and you have the flexability to reach any spore on that side of the room quickly.
Four Horsemen - when either tanking at the back or being at the front place a portal on the opposite side of the room to quickly get to the otherside of the room, saves time an allows you to swap sides faster.
Sapphiron - really handy for getting out of blizzards just place it away from where you stand.
Sartharion - Place the portal in one of the known gaps an simply teleport into it when you see waves of flame , really quick an saves you panic time.
Malygos - the most handy one, allows you to get out of vortex when placed in the middle of the arena, simply place it where the summon orb is, then in vortex spam teleport an you will get out giving you 5 - 10 secs to continue dps !
All of these combined shows the uses of teleport , i use it in almost every encounter but these are the most relevant for increased dps results, i hope it can help any other warlocks out too.
hope it helps