This one's a classic, but it works in Red Dead Online, too. If you want to make money, sell as much stuff as you can to the various shopkeepers of the world. Check cabinets, safes, chests, and everything else on which you can get your grubby hands. This extends to the people and other fauna you find yourself murdering, also. Leave no stone unturned in your adventures around the Western plains, and you’ll have built up a little nest egg before you know it.
Do the story missions, and do them well
While the game's story missions take a bit of time to complete, you can turn them into an excellent money-making opportunity if you’re willing to be meticulous. Check for bonus requirements and then tick them off as you go to help boost your earnings. It’s also a good chance to loot everyone and everything, too.
Go on treasure hunts
You’ll come across Treasure Maps periodically as you go level up online, but you can also seek them out by completing Gang Hideouts. If you visit them and kill everyone except the leader, you get the choice to spare or kill them. Either way you’ll have a chance of plucking a map from their corpse or from a nearby lockbox. Following these maps to where X marks the spot is a great way of injecting some extra cash into your life.
Go hunting and fishing
Hunting animals and selling their pelts to butchers is another good way of earning money. You just need to make sure you try and kill the beast with a clean headshot or a direct hit to a vital organ if you want to get the best possible pelt. You also need to consider the animal's state: a sickly animal will return a worse pelt, so try to only hunt animals that are feeling fighting fit.
Fishing is an efficient quick Red Dead Online money pastime, too. Once you unlock the ability to fish—you get a fishing rod at level 14—you can happily catch as many fish as you can carry before selling them off to collect some decent cash.
Get good at the Showdown Series
If you want to earn serious dosh, then it pays to be good at PvP. Each of the playlists award you money just for competing, but you’ll receive substantially more if you can win. Of course it's challenging to come out on top against real-life players, but at least you get a decent sum just for showing up.
Much like in real life, if you can avoid spending money needlessly, then you’ll have more of it. Simple, right? A lot of this comes down to not buying weapons unless you really need them, and not spending money on tonics or other items unless you’re heading into an important story mission.