Hey all.
I have made tons of money in this game and I figured why not to share the wealth....
First tip, its small but its Garlean Steel items, Joints/Plates/whatever, people usually undercut eachother so much taht they end up selling lower than 44gill (NPC Price),purchase all those and vendor them. If youre patient you'll make big money.
If you prefer the action way of making money, with you doing something and not waiting for others to slip up.
You pick a class of your choice (create a new character) I advice you to not make a Limsa Lominsa starting character as you cant really get to Ul'Dah and Gridania. You level to 10, you level the 6 professions you have eligibility to do, and then you sell the shards. It is a lot of shards, and you can do this in about 3-4hours, it makes you a formidable amount of money. Obviously it still deponds on the market as well, but don't sell shards if its too low market price currently. Save them and sell them later, this has made me a formidable amount of money. 1 profession yields around 50-80k, really depending on the market price.
Get farmin' boys, hope it helps!