Here is the best way I have found to level fishing. And the way that makes the most sense for when you go to level cooking as well. In this guide ill do my best to cover all details for an easy 99/120.
So we to begin fishing you will want to go to the fishing guild. Follow these pictures and you will be there in no time.
First step: Find the floating Bookcases.
Right Click and go to teleports
Click option #5 and go to Skilling.
Click option 1 and go to fishing:
Lastly click on fishing guild:
Levels 1-15 - Shrimp (Small Fishing Net)
Levels 15-40 - Anchovies (Small Fishing Net)
Levels 40-50 - Lobsters (Lobster Pot)
Levels 62-76 - Monkfish (Small Fishing Net)
Levels 76-99 OR 76-85 - Sharks (Harpoon)
Levels 85-90 - Cavefish (Fishing Rod + Fishing Bait)
Go back to the bookcase and use the MINING teleport to LIVING ROCK CAVERNS. The mobs will be hostile so be aware.
There is a Cavefish pool for those of you that have the donator rank located at home. It is to the right once you walk out to big front door.
Levels 90-99/120 - Rocktails (Fishing Rod + Living Minerals)
For those of you that want Rocktails go to the g.e and buy Living Minerals, Go back to the bookcase and use the MINING teleport to LIVING ROCK CAVERNS. The mobs will be hostile so be aware. If you are an ironman and you cant buy Living Minerals then kill the mobs down in the cave and mine them + pick up their drops.
IF you are a Donator you can use the Rocktail Pools located at home just out the front door to the left.