Instructions
Turn on your Sims 3 game, and open up your main Sim house. Click on the map icon on the left side of the screen. Choose a destination for your Sim to go, such as the park.
Wait for your Sim to reach its destination. Once you see the icon of your Sim reach the destination, click on its face icon on the left side of the screen, to instantly go to where the Sim is.
Search around the area where the Sim is, to find something to pick up. No matter where you are in the town, you can find seeds or precious stones hiding around. When you find one, click on it, and it will automatically go into your Sim's inventory.
Head back to your Sim's house by clicking on the little "head home" icon by the Sim's face icon on the left side of the screen. Watch as the Sim heads back home -- by walking, running or driving -- depending on the Sim's available modes of transportation.
Head inside the home, and open the Sim's inventory. The item you picked up will be there for you to place somewhere or use in some way.