It'd be interesting to get random chance and occurrence like you would over the phone like in sims 1 and 2. Gaining money due to a prize or something or just losing money. Kinda miss that with chance cards with jobs like being able to lose skill points and such.
Maybe make a property for your sim or any kids that get old enough to move out and give them a chunk of money to buy or build their home? I actually installed a mod where it'd charge my sim for visiting certain lots much like a entrance fee.
Or you can donate money if your feeling charitable :V