My AFK farming machine.

[Camseedood]

The title says it all

This makes it so you can wait for an hour and then go to an npc and just sell the things you get.
Wait.
.Collect
Sell.
Repeat.
EASY.

 

[Jectu]

If the farms' main intention is getting gold, I'd recommend setting up farms for events like the pumpkin moon/frost moon. You can get several platinum a night from these events if the farm is set up well from the enemies as well as from selling items.