Crafting is where most of mine comes from, with the occasional burst from selling gathered materials. At one point Doman Iron Ore was 3k each on a patch day, for NQ. I sold over 2000 ore that day.
Furniture is so insanely profitable its hilarious. Things like mounted box shelves, imitation windows, tier 3/4 aquariums, etc. are very easy to make but sell for ridiculous amounts sometimes. Even some items that you need special diadem or airship voyage mats for can be sold for FAR more than the mats cost to buy. Its all about spending some time researching the MB to find what sells and keeping those items listed as often as possible. I usually have well over 100 pieces of furniture listed at a time.