Here's a few tips for those in the early stages of Final Fantasy XIV! Most of these are things I wish I had known earlier in the game.
When you're handing items over to NPCs, you don't have to hunt through your inventory and drag everything over. Right-click on greyed-out item in the turn-in window, and then click on the item it bring it over.
You can drag emotes directly from your Emotes window to your hotbar. This is good for quests that require them!
You can choose up to three favored teleport destinations. Making a destination as favored halves the cost to teleport, so this is important!
Enemies don't move when activating and using a special ability. Stay out of the red areas!
Linkshells are personal chat channels, you can join up to 8. Free companies are player guilds. Grand companies are story factions aligned with each major city.
The game will auto-sort inventory for you. Go to System > Character Config > Control Settings > Character Tab > Auto-sort Inventory.
Despite what you think, you can still get loot off of enemies that are tagged by other players, as long as you do 30 percent of the damage to that mob. (10 percent if there's more than 8 players attacking it.)
In your starting city, find the Potwatch vendor in the marketplace or an alehouse. Buy some orange juice. This will make sense at level 15.
Rest experience is a percentage based on your current level. Switching to a lower-level secondary job and using that rest XP means you're not getting the full value out of it! 20 percent of level 15 is better than 20 percent of level 3!
If you go to sell your old gear and it says that you've spiritbonded with it, keep it! That gear can be turned into Materia when you reach level 19.