Lots of Life skill products are in high demand. However it is really boring to make them. Also, not all Lifeskills can make money in Mabinogi. Tailoring is one of the ones that lose money because most clothing can be bought from NPCs, obtained from gachapons, or found as rare items from monsters and dungeons. In general, any Lifeskill that requires another Lifeskill's products to level(Mabinogi powerleveling) up are not lucrative because the cost of the materials far outweigh the gains. You can make the most money from Refining, Weaving, Metallurgy, and Potion-making.
Refining and Metallurgy make good money because people buy up Iron Ingots and Gems to do Blacksmithing. Weaving is good because weaving products are used in blacksmithing, alchemy, tailoring, and handicrafting. There will always be a buyer. For potion-making, the money(cheap mabinogi gold) is almost all from mana potions and you do need to dungeon a fair bit to obtain herbs, unless you own an herb pet. As long as you charge a reasonable price, a lot of high leveled mages will buy your potions because its faster than making it themselves.
