Money is always an issue in a lot of RPGs, as you will need to keep up with equipment from shops and sometimes, enemies don’t drop a lot of it. In Dragon Quest XI, gold is something that shouldn’t be too much trouble, especially for equipment, but one of the best things you can use money on is buying materials for forging. There is no set method or enemy that drops a lot of gold in itself, so you’re stuck with just normal grinding if you’re looking to purchase a shiny new weapon or piece of armor. Unfortunately, you don’t really get a good source of money until much later in the game.
It isn’t until you have access to the final part of the game that you can farm money. Once you are in that section of the game, wait until your characters have access to the skies again and head to The First Forest Whale Way Station, which is just north of Yggdrasil. You will be hunting some enemies here, called Hooper Dupers, but you want to make sure you have a few things ahead of time. Erik will primarily be your go-to character here, but you need Half-Inch on him, as well as the Sticky Fingers passive (both in the Guile tree). You can also increase the chance of stealing something by crafting Robber Gloves and getting them to +3.
Once you have all of the above situated, go to the location listed above and hunt down some Hooper Dupers. These enemies have a shield called Devilry Drinker in their common slot. That is what you will be stealing, since those shields sell for 30,000G a piece. So, you simply get into battles with them, steal the shields, then either flee or defeat all of the enemies. If you want to get even more into it, then you could also equip drop-increasing gear on your party and try to get more shields to drop. Note that the Hooper Dupers can also drop Seeds of Sorcery, which increase a character’s Magical Might stat.