Easy money
If you buy the four special upgrades in each restaurant (shown by a star next to the object after it is purchased), you will get a tip bonus in that restaurant.
Bistro: Lights ($200), Aquarium ($300), Rugs ($200), Kitchen ($500)
Cafeteria: Plants ($200), Jukebox ($300), Floor Lighting ($400), Cadillac Table ($300)
Italian Restaurant: Kitchen ($400), Fireplace ($400), Paintings ($300 and Plants ($200)
Sushi Bar: Aquarium ($300), Paper Sliding Door ($200), Koi Carps ($400), Bonsai Trees ($300.)
The Park: Grass Lawn ($400), Popcorn Stall ($200), Counter ($200), and Ice Cream Van ($300)
Buy all available items for sale in decorations. Try buying at least buy the most expensive item to start.
