Turn on the Cheat Console (It's actually called the Debugging Console) on, hit Control + Shift + C, then enter some codes. Cheat codes are case-sensitive & you have to pay attention to where spaces are when typing in codes.
Open more options in "Create a Sim" screen: First type in boolProp TestingCheatsEnabled true, then Shift + N. You can change general appearance (such as weight & clothing) & more. In the game itself (not in Create A Sim), you can Shift + Click on the Sim you want to change.
Never Pay Bills: In Build or Buy mode, enable Cheat Console & enter moveObjects on. Then select & delete the mailbox.
Speaking of money, you can set the amount of money for a family in the Cheat Console by typing familyfunds (the name of the family) +(the number-amount you want). Example: familyfunds smith +10000
Free Groceries: When the grocery delivery comes, just don't Greet. The delivery person will give up, put the gorcieries on your front step & leave without taking payment.
No Censor: Enable the Cheat Console & enter intprop censorgridsize 0. That's a "zero," not the letter "O." The normal censor setting is 8.
Set Floor Tiles Outside of Lot: In the Cheat Console, enter boolprop locktiles off. To re-enable normal settings, just type "on" in place of "off."
Elevate/Lower Floor even when filled with objects: In Cheat Console, type in boolprop constrainFloorElevation false. To re-enable the elevation lock, just type "true" in place of "false."
Another way to maximize only the specific Motives and/or Skills you want, enable the "boolProp testingCheatsEnabled true" code, then go & select a different family. A strange code will appear at the top right hand corner. If you look at a Sim's needs, you can click & drag on each Need and drag it up or down, whichever desired. You can also increase the skill points of your Sims in the same way.
Another easy way to close the Cheat Console: exit
This is more of a "glitch" than a hint or cheat. If you're ADOPTING A CHILD, when the Social Worker comes DO NOT Greet the Social Worker BEFORE she rings the doorbell; She'll never leave & you cannot buy items, build or save the game!