I have normally have Full Frost spec for this stuff
Go to Scarlet Monastery Cathedral. Run all the way to main Boss Chamber. Will be easy to dodge aggro as you are level 70. Kill pats if you can't get around. With a little practice you can get there with only 1-2 fights tops. Once inside you need to move down right or left side and dodge pats so that you are standing close to Mograine without aggroing him. Now the fun begins. But first Make sure you have all you spell cooldowns up so you can use everything at your disposal. Make a Mana Ruby for backup mana. You can use potions but these cost money and counter your profit. Your decision.
Ok, now that you are ready you can start the fight. Put up Ice Barrier and pop Mograine with a frostbolt and he will rush you and aggro the whole cathedral to come kill you. Take hits from Mograine until your barrier is removed. You will see the other mobs rushing you from all directions. When Barrier is gone pop Ice Block. This is the focal point of this run. Ice Block gives you few seconds for all the mobs to gather around you without damaging you. Now they are all nice and packed for some AoE blasting! Ok, as soon as Ice Block expires you want to pop Frost Nova and Ice Barrier again as you strafe out of the groups melee range. Now commence to laying on the AoE damage. Remeber that Mograine can't be Frost Nova'd so that is why you put your Ice Barrier back up since he will be beating on you while you are AoE killing his minions. once all the people are dead, Mograine should be less than 30% so finish him off. Immediately pop Evocation to refill mana because Whitemane is on her way. As long as you didn't end up close to her spawn point when you killed Mograine (practice will show you to finish Mograine towards the middle of the chamber) then you will get off a full Evocation for plenty more mana. Now kill Whitemane and Mograine again when she resurrects him. This little run nets me 6-8g in change not to mention any vendor trash, greens, blues and cloth that drop off all the mobs you just killed. Plus if you are an enchanter you can DE the Boss blues from Scarlet Commander Mograine and HIgh Inquisitor Whitemane sell the shards in AH. This run take might 10 minutes after you run it a few times to get patrol behaviors memorized and I average 12-16g after counting all the change, cloth, random greens and blues, plus shards. This is normally how I do my aoe stuff
Frost Nova (then strafe)
Flamestrike
Cone of Cold
Cold Snap
Frost Nova (and strafe)
Flamestrike
Cone of Cold
Blink (away from mobs)
Blizzard
Arcane Explosion (repeat till all dead except Mograine)
Kill Mograine and Whitemane as explained above.