Phase 1 of yogg seron involves spawning and killing faceless guardians next to Sarah in order to kill her. This phase can be extremely difficult for new guilds on Saron so I figured Id share this little exploit.
Mages can cast invisibility on themselves, run into the room, run through 2-3 clouds and run back out.
What this does is spawns 1 add per cloud ran through while leaving the raid out of combat with Sarah and the Yogg Saron encounter. The raid then can freely and easily dps down the 3 adds to low hp, then all at once pull them down to sarah and gain a large head start on the first phase.