Always do your Hunting Logs, both for class and for GC. Get your friends to help you with them so you can tackle the higher level ones if you're under level to solo them.

DO NOT SKIP THE SIDEQUESTS. I skipped some earlier on hoping to use them for another class later on. Big mistake. I'm consistently ending up under level for the next story quests and have to end up FATE grinding or doing dungeon runs to catch up in XP.

You can do FATEs to fill in the void if you run out of story quests and are waiting to do a dungeon.