With the new beast tribe coming out. If you thought you'd get your last unleveled class to 60 (you have everything else at 70), and you got your fisher from sub level 10 to level 58 daily turn ins you bought off the market board, you have absolutely no idea what you are doing, then you need a guide to fishing. And for more on FFXIV Gil, go to FFXIV4Gil.
● Turn on Collector's Glove. Catch valid-to-be-collectables fish. (Not all fish have a collectables version; you can still catch them with Glove on, they'll just be normal fish.) The bigger the fish is, the higher its collectability rating (𝕔). Whatever NPC you turn collectables in to will have minimum 𝕔 requirements; if a fish's 𝕔 is too low you can't turn it in, it's junk.
● HQ fish are always going to be bigger than NQ fish so ideally you catch HQ fish. Beyond that the exact size (and thus 𝕔) is RNG, and you can get screwed over by bad luck. This makes it a lot simpler/easier to do than BTN/MIN collectables but you're at the mercy of RNG. Good luck.
Catching HQ fish:
⒈ Get as much GP as you can.
⒋ Wait until something bites
⒌ Use either
▶ Big tug on the line → Powerful Hookset
▶ Small tug on the line → Precision Hookset
⒍ Repeat 3→5 until Patience fades
⒎ Start over from 1 until you have all your fish.
Catching specific fish instead of whatever the heck the ocean gives you: Determine which fish you want to catch. Use external sites/sources to look up the correct combination of fishing hole, bait, time, and/or weather. No matter what, you need some cheap Final Fantasy XIV Gil to guarantee your better play in this game.