Making shards- make shards for gil or just sell the one you get from mobs
> Stock up on Lightning shards (drop by beetles and sheeps outside of Limsa or from bees in Grid.) or buy from Crystalier's Wards in Ul'dah (`a little suggestion- buy diff. starter weapons so you can change to diff. classes if mob stop dropping shards cause of your higher rank, also not a bad a idea to level a bunch of classes to certain levels to get useful abilities.) Buy tiger cod and maiden carp from Holasfhis (7,6 Upper Decks, Limsa) to make wind and earth shards that you can sell in Ul'dah's wards or for leveling your crafts; since weaving and woodworking uses a lot of earth and wind shards as does lots of other crafts they are better to sell than other shards. Making shard from fish required you to be an Alchemist, >Weathered Alembic<, you can begin at rank~1. It takes four lightning shard and a fish to make 12 shards of an element. Try to price your shards/items at around the market's price so that your stuff will appear on the item search (it only list the twenty lowest prices for that items)
Things to farm and sells
`Sheepskins - 22.50% Drop from Lost Ewe(also a nice source for wind shards) at (25,41) in Lower La Noscea, south from Limsa. Sell these in the MW, ~3-5K Gil depending on you server, higher for +3's.
`Marmot pelts - Drop rates same as above. Marmots are found outside Ul'dah, Lim-....o_o, well they can be found anywhere really. NPC these, 350-ish to ~450gil for one, unsure of the exact amount.
`Other - Most things you should probably sell to NPC's, except for skins, hides, and some pelts, those should be sold in the wards. Logs and ores from botany and mining should maybe be NPC's unless you're a botanist and/or miner and can gather a bunch to sell on your retainers(don't put things that that are hard to sell, like marmot meat or rat tail up for sell), check market price to see what has value or not, most things aren't worth taking up a retainer bazaar space imo. Fishing can also helps with making Gil since people buys fish for ranking alchemy, but I'm not much of a fisher so not really sure of all the details.
Crafting is a big part of the game and can make you the most money therefore it's a good idea to pick up on a few crafts. It can be a big grind and because of how it functions atm, can takes a lot of time until they either add better way for rank up crafting or improve on the crafting system but for now just try to take it slowly if you're playing casually. Post any questions, if you need help on what to grind at certain ranks.
Let see, what else..., -do your storyline quests (one appears every few levels or so, they can give a nice chunk of Gil and SP), get leves done every 36 hours for Gil along with the farming/grinding and crafting, as well as any quests that you might be able to pick up and you be should be able to make some decent Gil. Hope this helps.