Ideally this is your gameplay loop: Early game quests for 15k for your first workshop, this workshop will pay for your low tier army. Then grind more for another 15k while you see your workshop slowly going up in profits. Once you get the second workshop running, you can start upgrading your units.Caravans not making money, some losing money. I have 4 caravans and its rare if any them make money, seems like only happens once a week. One of them is even losing money, about -1000 denars a day. The caravan that is losing money is also going back and forth between the same 2 cities. I dont have any economy related mods.
For workshops, try changing them to tanners. They seems to be the one with the most consistent income. All of my workshops produce 300 or more and they're just all tanners. This, you don’t need to give them leather and even in the worst city’s Ill still make 250+ a day. This worked until the new patch.
Check the great video "I Spent 50 Days as an ASSASSIN in Bannerlord" by Arean, really nice story telling! A lot of the features of Fourberie are show cased, so it may be a good inspiration for your new campaign ;) Save compatiblity notice As already announced here, this version is not save compatible. You will need a new campaign.
The simple answer is, if you want to make money on a workshop, just buy a pottery workshop from a settlement with a clay resource. There are a few in the Battania lands and I always buy one in Danaustica. This is objectively true and easily observable in every single playthrough. Just try it. Nothing will make more money than a pottery workshop.