Just a simple way I found out last night.
Requirements:
-ENCHANTING-
A group of 2-4 people makes this a lot easier.
Basically, go farm a lot of Necrotic Runes and spend them on Argent Dawn Banners. These sell for 8 each and DE to Large Prismatic Shards.
Last night with 3 friends (Feral Druid, Holy Priest, Frost Mage and myself, Marks Hunter) went around doing invasions. We did this at about 4am Server Time in Blasted Lands when it was completly empty. I mean, not even 1 other person besides ourselves. There were around 5 camps no more than 100 yards apart and we went through 1 by 1, pulling EVERY mob and aoe'ing them down 1 camp at a time until they were all on 0 health so we can summon the big guys. After we could summon them, we pulled all 4 and nuked, each person got a stack of 30 each. Simple. This took us around an hour at max to clear all of the camps in the area and we each ended up with 180~ shards each (We're all T6/Sunwell geared).
Nice and simple, I went and bought all the banners and DE'd as did one of the other people in my group since there isn't much need to buy anything else. Made around 300g-330g from my lot since on my server they sell 15g each. Very easy money if you ask me.