Using the "testingcheatsenabled" Command:

This testingcheatsenabled cheat allows you to do several useful things when used
properly. First, hold CTRL+SHIFT+C (CTRL+SHIFT+WindowsKey+C for Vista) and enter
this code: testingcheatsenabled true
Now, hold SHIFT and click your letterbox. This will provide you with these
options:
• Make All Happy
• Force Visitor
• Set Career
• Set level
You may also hold SHIFT and click on Sims to get these options:
• Add Sim to House
• Change Sim Traits
• Force Aging
Work place
• Force Opportunity
• Force Event
• Force All Events
Any Sim
• Trigger Age Transition
• Modify Traits
Active Sim
• Modify Traits for Active Sim
Non-household Sim
• Add to Household
Moodlet Panel
• Remove a Moodlet from the Moodlet Panel.
Note: If it is motive induced, the bar related to the negative Moodlet will be
completely filled.
In Ground View mode, hold SHIFT and click a spot and your Sim will teleport to
it.