-Pause game play when there is a person on the road to your park and check how much money that person has. Make the admission to your park $10.00 less than that amount. Rename the guest "Melanie Warn" to make him very happy. Resume the game and the guest will pay the admission most of the time.
-Grab a guest that is rich and is very thirsty or hungry, or has to go to the bathroom, etc. Go in the water and create a little island with whatever he is in need of -- for example just a bathroom. After that, check to see how much money he has. Put him on the island with the bathroom costing the amount of money he has left. Note: Your park rating will go down.