Wow, just when I think the guide is almost ok... that's such a fundamental question it never occurred to me to wonder where the answer was written down!
Anyway, Tailoring and Smithing runics are rewards from the
Bulk Order Deed system (which page explains quite a bit about BODs but not actually how to get them - click on a Tailor or a Blacksmith and choose "Bulk Order Info" from the context menu.
Fletching and Carpentry runics are rewards from quests in Heartwood (the Elven city - there's a teleporter in the middle of Yew, and you need the Mondain's Legacy expansion to go there.) Sadly, I don't actually have more detail on those quests right at hand, but I'm confident the rest of U.Hall will cover for me while I go write it on my to-do list