Any money making tricks?

[Kiryuu]

Can someone share me methods of making lots of money fast? I'm at overtime

[Falcon9a]

Yes, fighting humans gets your 1-5 equipment drops and they sell for quite a bit more than ingredients

[Afjklol]

I know its old but since this is bumped up, and others might have the same question, I'll answer as I just did my second playthrough and on overtime on NG+

As mentioned above, human enemies give pretty decent money due to dropping equipment which you can sell. For the main game, human enemies pop up the most in Catacombs and Traveler's road which you can farm early to mid game if you really need cash. They spawn in certain areas only, so look at the enemy list to pick which one to go to. But I don't recommend it because if you want to Plat the game in one run, you don't have time to waste on those areas solely for money.

Late game, you can craft and equip 'Bunny's Tail' (to increase rare item drop) and go to floor 9 of Orthogalaxen and kill 'Grow Plantze' which can drop 'dunkelheit' that sells for a lot. It is a useful crafting item but this is the recommended method to get the 'Rich' ending without NG+. Just make sure to craft 'windriders' (if you get Pamela to friendship 25, you can wholesale it). 'Windriders' let you teleport back to the atelier, so you only use one day to travel to Orthogalaxen and once you cleared the room, just use the item to teleport back.
Just to be clear, you probably want to craft 'Bunny's Tail' and a 'Windrider' as early as possible since there's more free time early game due to easier assignments. Late-game, you start to have a lot of events, crafting, and money farming (which takes a long time) competing for your attention. Crafting those stuff late-game will use up valuable days for other stuff.

For overtime, Orthgalaxen is still probably the best active way to earn money, but you can also now use Hom to gather at Orthogalaxen for rare items. Make sure to do enough of the OT assignments to unlock Hom Gathering Lv.5 and if you do, he/she will get you 'dragon horn' and 'dragon scale' from Orthogalaxen which sells for a lot, although not as much as 'dunkelheit.' This is a nice passive way of getting money.

Machina Domain and Abyssal Tower also drop very high quality materials and gears. Those high quality gears can sell for a lot of money but since there are fewer enemies and gathering spots, it is harder to get a lot of said items. However each zone is only 1 day, so once you arrive, you can stay there for a long time. Machina Domain is better since you don't need 'air drops' to breathe. Just make sure to craft 'secret bag' decoration so you can access your container without returning to the city. This way, you can pick a large amount of high quality equipment continually. That said, I think Orthogalaxen is the better money farm unless you also want to get materials with endgame traits at the same time. Orthogalaxen also has much weaker enemies too.