Currencies!

[Bixby]

Soldiery/Poetics: Unlock and run daily roulettes. That'll cap your poetics each week, you shouldn't need to specifically farm them unless you're getting toward the end of the week and still need some or you're in a rush to cap them right off the bat. If that's the case, spam Expert even after it's done. For soldiery, you can either keep spamming dungeons, or story roulette (there's a new player to get the new player bonus pretty often). If you can get a good group together for it, Hunts can still be a decent source of soldiery, but that's not a small "if."

Company Seals: FATEs if there's a zone where a good number of people are doing FATEs (the ROG/NIN rush is dying down, so this isn't quite the sure thing it was a week ago). Grand Company leves if not. Hest & low level roulettes on non-50 jobs, too. Oh, and also Expert deliveries with all the gear dungeon/tome/etc. gear you upgrade out of. Roll on everything just for this.

Gil: Gather, craft, and/or spiritbond. There's no one-size-fits-all answer. For gathering and crafting, you have to research a bit to find what sells & why (if you don't know why people buy something, you're just going to be surprised when the bottom falls out of that market). Spiritbonding is less research-intensive, but a bit more luck-based.

Allied Seals: These only come from Hunts, so... Hunts. Between "nerfs" in the last patch and the ROG/NIN rush, Hunts have died down quite a bit. And the scene is different from server to server; on some servers, there are Hunt LSes that you can join "permanently." On some servers, the Hunt LSes let anyone who's actively hunting join, and leave/get kicked when they're not actively hunting anymore. These days, though, with so few people doing them, it's hard to say how things are going.