Currently on my 3 box shaman I have:



Main :: herb/skinning (as to not worry about switching screens)

Alt1 :: Alch/Inscript

Alt2 :: Leatherworking/Tailoring



With this setup I can cover all bases with elemental. Crafting some spell dmg gear here and there with leatherworking, having tons of potions/elixers farmed, self sufficient with glyphs (they still run 50g+ each currently) and scrolls and even craft the enchantment threads for all my alts.

Also, I do have 3 other mains I play, including a prot pally, resto/feral druid and mage, all of which currently are miners, and one of which is an enchanter.

So I'm covered on all bases =)