When you are on the second restaurant customers will pay you more money than normal when you keep giving them more beverages when they are at full hearts.
If there are three or more packs of guests and your table is full click the table that is ready and go to the Podium Heart. Serve the food then go to the Podium Heart. Keep repeating the move until the table is empty.
When you have a customer that is at 1 Heart Level and your Podium Heart will not hold them long enough you can move the pointer over the customer and 'hold' them until your Podium Heart is full. Doing this will prevent the customer from leaving.