If you are leveling up fishing, or simply want to grind some for the Fishing Artifact, using the Ancient Vrykul Ring is a really nice way to get levels and artifact power very quick and easy! In order to get start on this method, you first need to buy a few Arcane Lure from Conjurer Margoss. This increases your chances of finding bait by 100 %, so you will get the ring a lot faster. Alternatively, you can buy the Ancient Vrykul Ring from the auction house, but it's really expensive there!
Anyway, head to Stormheim and look for pools until you fish up an Ancient Vrykul Ring. Once you have this item you will be able to spot hidden pools for 5 minutes. Head to 35.3 22.8 or 42.2 61.2, because this is where these pools are. You can fish in these for 5 minutes, and they will not dissappear like the regular pools! Each catch gives you a rare fish, and you will guaranteed get a new Ancient Vrykul Ring before the buff timer expires.
So to gain fishing skill or artifact power, just keep fishing in these special pools for as long as you can manage. The best part about this method is that you don't even need to move, so it's really easy to combine with Netflix while you fish. Happy fishing!
If you end up with some spare rings, put them on the AH for the people who wants to skip getting the ring themselves, because it is usually worth around 2,000 - 5,000 gold.