1. If you break the MC just before an add wave spawns, adds will run to you instead of Razorgore
2. While Razorgore, you can keep up to 3 dragonkin hibernated
3. If your class allows it, use healing spells (particularly HoTs) to generate healing aggro. You can also end the channel by castng an instant healing spell on Razorgore to heal him.
4. Never attack as Razorgore
5. Never let Razorgore be attacked from the back
6. If you need Razorgore to escape and are on the elevated areas, jump down as adds have to follow the normal path
7. MC Razorgore ASAP, but try to clear the orb side of the room first
8. Be very careful about AoE if Razorgore is near your character.
---------- Post added 2012-12-10 at 11:17 PM ----------
If you're having trouble getting enough shatter hits, consider trinkets that spawn a pet that melees. For example, Netherwing revered trinket, engineering on use battle pets, Cornerstore Grimoire from Onyxia, Furlbog exalted trinket, and others that I'm probably not remembering.