This is the best Zenny / Hour Spot I have found so far.

To get you started uncover the Area 8 Pop-Up Camp (Safe) in the Scarlet Forest
This Camp is in the upper Area of Section 8 on the Map.

1. Build the Pop-Up Camp from your Base Camp
   
2. Equip your Capture Net, NO Fishing Rod required!
   
3. Get into the Pop-Up Camp, select Rest in the "BBQ Menu", choose Plenty and Daytime for best visibility
   
4. Leave the Camp, move to the right. The Yellow X Marks a Spot for a Crab which can spawn sometimes and grants you 1 Ancient Wyvern Coin when captured
   
5. Wait a few Seconds for Fish to spawn in, quickly Capture them to get several in one Net throw
   
6. Move to the upper Fishing Spot which you can reach by diving, the Yellow X marks the second Ancient Wyvern Coin
   
7. Catch all Fish
   
8. Move / Teleport back to your Pop-Up Camp and repeat
   
9. Sell your Scales from your Camp via "View/Sell Items"

Each Goldenfish gives you:
50 Guild Points
1-3 Golden Scales = 1000Z each

Each Platinumfish gives you:
100 Guild Points
1-3 Platinum Scales = 2000Z each

A single Run takes 1-2 Minutes and grants you 25-45K Zenny.
30x Ancient Wyvern Coins can be traded in for 1x Golden Melding Ticket via Nata -> Gawdygog.
You will also Make several hundread Guild Points as profits, even when spending 300 to reset the Fish.
This farming will also get your Item Deliveries from Nata stocked up, so visit him frequently while doing this!

Only Golden-, Platinumfish and Escunites spawn there.
Ignore the Escunites, they don't drop Items and only grant 20 Guild Points
The Grand Escunite spawns here aswell, this one is required for the last Fishing Sidequest and needs to be caught with the Fishing Rod.

This is a very easy and cozy way to farm up your basic Resources, best watch a Video or sit in a Discord while farming :)

Hope you find this helpful, please share your findings aswell!