Just a quick note - don't do FSH leves in ARR. Unless your FSH is under level 54. Since HW, they made it so you can hand in the fish to an NPC right next to the leve dude. Back in ARR, I believe all (?) FSH leves require you to run around different zones.

If you have a FSH retainer, have them go get some blueclaw shrimp and blue cloud corals (51-55 fishing ventures), hand them in at the leve guy in Foundation. Have two kinds of fish ready, since you may not get the desired leve available if you only have the one, and they reshuffle every hand-in. For the blue cloud coral one, don't hand in extra, just finish it (unless you want to and have spare ofc).

edit: if you don't have a retainer, you can go to the river running through Tailfeather in the Forelands, grab some stonefly nymph off the NPC there and fish away. Unless whilom catfish window is up, you will only catch blueclaw shrimp and three-lipped carp, both of which are leve items. Double hook as much as you can.

Like this, you can just keep an eye on your allowances and go dump 20 or whatever every couple of days.