Get a current bus schedule. If you time it right, your wait can be considerably shorter than if you just randomly show up.
Buy tickets in advance. Greyhound sells tickets far in advance and city buses typically sell books of tickets with no expiration date. Then you don't have to worry about cash and correct change when you're ready to hop on board.
Find a spot, usually downtown, where you might find your friends and other folks who move around town on the bus. They will be hanging out, smoking, playing music and making the whole bus experience a trip in itself.
Wear your MP3 player or other music device to pass the time. Download "Do the Bus Stop" and have a blast at the corner or station while you wait. Portable speakers will allow others to hear the tune with you and turn the whole event into a party.
Look for better bus stops that get you where you're going with less hassle, fewer passengers and a better chance at getting a seat if your current bus is getting too crowded. In bigger cities, check the bus schedule for other alternatives. Smaller towns have fewer options, but are worth investigating.
Catch up on your reading. Plan a wait into your schedule and bring the magazine, book or mail that you've been putting off reading. You won't have to watch traffic on the bus nor be bothered by fellow passengers if you prefer not to.