Since I despise crafting and would rather farm mobs for gil, what I do is find which gear people want the HQ versions of, do a bit of research with www.yg.com, and go out and get the HQ drops to sell. I've made upward of 45mil from farming such items in a relatively short amount of time. Also, managing your retainers well and selling what can actually be used in a synthesis could keep you from actually ever having to farm just to keep yourself up and running. I do keep a window of YG open just to check items that I've gotten randomly while out grinding and whatnot.

Just like Kala said above me, he uses Vulture feathers for arrows that will obviously sell well. For the right price, I'm sure crafters would like to be saved the headache of actually doing the farming themselves.