Just wave. If you are not at a designated bus stop, you can still wave down The Bus. Make sure you're at a corner and put your hand high above your head and wave so the driver can see you. The driver will be happy to pick you up.
Of course, if you are anywhere near a designated bus stop, that is your best bet, and your arm won't get tired.
Getting off The Bus
Let the driver know you want to get off The Bus at least one full block ahead of your stop by pulling the "stop requested" pull cord. Don't worry, the cord does not activate the brakes. It just lets the driver know that you are about done with your trip.
You can get off anywhere along The Bus route as long as it's safe to stop.