The Best Ways to Make Money in the Sims 3

Painting

Buy an easel and sell paintings. Go to Build and Buy Mode, buy your Sim an easel, and place it anywhere in the world. Go back to Live Mode, click on the easel, and select to paint a big, medium, or small painting. Sell your painting when it is finished. It will not sell for much to begin with, but as your painting skill increases, you will be able to sell your paintings for a lot of money! The larger the painting, the more it'll sell for. Paint a big painting as it may sell for more

Writing

Publish novels from a computer to earn extra cash. Go to Build and Buy Mode and buy your Sim a computer. Go back to Live Mode, click on the computer, and select the Write interaction. Choose whatever genre you want. Publish and sell your book when your Sim finishes writing it. If it is good enough to be published, you may see it in the library or bookstore's bookshelves! If you can, buy your Sim an expensive computer so it's less likely to break.

Inventing

Make new things to make a living. Go to Build and Buy Mode and purchase a workbench for your Sim. Return to Live Mode, click on the workbench, and select Dabble. There will also be the option to purchase scrap metal, which you can do but a) you won't need scrap metal just yet and b) if you have Sims Pets 3, then you can adopt/buy a dog and get it to give up scrap metals. Sell your creation from your inventory after making it. Your Sim's first creation will only be a toy and it will not sell for more than a few dollars, but as you invent more and more, your inventions will become wackier and sell for more! It's a good idea to build a separate room for the workbench as it takes up a lot of space. Sims 3 Ambitions is required to be able to invent/purchase a workbench.

Fishing

Sell the fish you catch to make an extra buck. Command your Sim to go to any fishing spot. Click on the icon near the fishing spot and select Fish. Sell the fish you have caught. The bigger and rarer the fish, the more money it will be worth! If your Sim isn't catching anything, try buying some bait.

Guitar

Play music in a public space to earn tips. Go to Build and Buy Mode and purchase a Son flux Guitar. Place it anywhere you'd like, inside or outside. Click on the guitar and select Practice Playing. Put the guitar in your Inventory, go to a busy park, select the guitar, and select Play For Tips. If you are good enough, you might earn a bit of money from people who are watching you play. Your Sim must have a 4 or 5 guitar skill level to earn tips.

Collecting

Find hidden treasures to sell for profit. Go anywhere outside. Look for things like small animals that you can pick up. When you find one, click on it and collect it. Go to your inventory and sell the thing that you just collected. The rarer the thing you collect, the more it will sell for. This method can be hit or miss as it is not really a skill that your Sim gets better at so it's basically your ability for this method, not your Sim's ability.

Mooch

Ask other Sims for money. Go to Create A Sim and create a Sim with the Mooch trait or select a premade Sim that is already in the neighborhood and has the Mooch trait to play as. Build up a high relationship with somebody who is rich. Click on the rich Sim, select the Special category and then select the Mooch category, and finally select the Mooch Big Amount of Money. It is best to become at least Best Friends with someone before mooching. Don't do it too often, do it only once or twice per visit with the Sim.

Cat

See if your Sim's cat will bring you money. Adopt or purchase a full-grown cat if you don't already have one. Click on your cat and select the Teach To Hunt interaction. If you have purchased a version of the game where you can control your pet (such as The Sims Pets 3 for PlayStation 3), instead of getting your Sim to teach the cat to hunt, simply click anywhere outside. Check your inventory to see if your cat caught anything. If they did, sell what your cat caught (they will probably catch a beetle). The rarer the thing caught, the more the thing will sell for! If you make the cat in Create A Sim Mode, give it the Hunter Trait and possibly the Adventurous trait. Note that if you use it too much your cat will probably get the Brain Hurts moodlet and you will not be able to teach your cat anything for several hours. Sims Pets is required for this.

Digging

Ask your Sim's pet to find buried treasure. If you have Sims Pets, adopt or buy a full-grown dog. If you can control the dog, while playing as your dog, click anywhere outside, select the Digging... option, and then select the Dig interaction. Go to your inventory and sell the item that you dug up. If you can't control your dog, get your Sim to use the Teach To Dig interaction on your dog often (if you use this too much on your dog, however, your dog will get the Brain Hurts moodlet and you will not be able to teach your dog anything for several hours). After a while of digging, you will find things that are even more rare and valuable which means that they will sell for much more money. If you do not have Sims Pets, click anywhere outside and instead of selecting the Go Here interaction, select the Dig Here interaction. This will dig a hole and you will possibly find something buried underground.

Guitar Extra

Play music for extra tips on the subway. Get your guitar level to 5. Learn a composition. Pause the game and stack up your action bar with 'Play (Composition name )'. For starters, it would usually be something like "yes mam, I do". Hit play. After the first line of each time, it's played cancel the action. Do this as many times as you are willing. Go to any of the subways and play for tips. At first, you'll only get maybe 80 - 300 per, maybe 30 minutes. As your guitar skill increases and the more compositions you play, you can earn a lot of money. In a small amount of time, you could be earning 40,000-100,000 a day. That's with maybe 6-10 hours of playing. This method requires the map Bridgeport for the subways. It comes with the 'late night' expansion.

Harvestables

Grow your own fruit and vegetables to sell. Harvest when ready. Sell the produce through build and buy. Or, sell it using the market stand at a community lot or the grocery store.

Future Lotto

Travel to the future to win the lottery. Fix up the Time Portal. Go into the Future. Go to the Park (where the City Hall will be located). Check for Lotto Records until you find one. Return to the present and buy a lottery ticket! This requires Sims 3: Into the Future.

Plants vs. Zombies Sunflower

Plant Sunflowers in your house to "grow" money. Place down some Plants vs. Zombies™ Sunflowers in your house outside. Wait for the plants to start producing Sun, then sell the Sun in Buy mode. Plant more Sunflowers in the house to produce more Sun over time. This requires premium content from The Sims 3 Store.