I haven't found this particular guide, so I might as well post it here.
In Ulduar, the conservatory (Freya's Room) full of herbs that respawn. (you may know where I'm getting to)
With a simple group, clear up to and including Kologarn (convince your weekly raid even), giving you access to stealth as either a druid or rogue around the conservatory.
With the new handy dandy instance lock extenstion, you're able to practically herb endlessly, and then wait for a 3 hour respawn timer, every day.
I honestly don't have pictures, because I don't have either a rogue or a druid, but I suggested it to a friend of mine and he confirms that it works.
Unlimited flasks for everyone!