I don't know about the higher level crafts, being new rather than a legacy player, but I think that selling things like Iron Ingots or Elm/Yew logs/lumber has potential, especially if you sell the HQ versions in small lots at prices that are reasonable rather than extortionate. This is particularly applicable for people who are, say, leveling smithing in Limsa but need iron. If you make it worth their while to just hop over to the market and buy your iron ingots, HQ or NQ, rather than airship to Ul'dah and mine/craft their own, you should move some, even if it won't be a billion gil overnight.

I know I was leveling up weaving and went to make myself a spinning wheel, only to find I lacked maple lumber. Since I have the carpentry to HQ the logs, I hopped over to the market, and discovered someone had put a dozen logs up for 5gil apiece. 60 gil for a lot of logs I can turn into HQ lumber is very worth the gil.

WTB ability to buy just 5 instead of 99 of something!