First, choose one of the following means of transportation: motorscooter, bicycle (with or without rikshaw), van that looks like it's been shrunk in the dryer, bus, cart pulled by donkey, buffalo or camel (yes, really, camel!), mini-car that maybe you borrowed from an amusement park ride, tuk tuk, small size pick up truck, or tractor.
Next, load in as many people and/or as much cargo as you possibly can. Now add more. People standing on the rear bumpers of cars is fine. People riding on top of the cabs of trucks is also fine. Three people on a bicycle? No problem.
Now you're ready to drive! Make sure you know where your horn is because you'll be using it as often as your gas pedal. Whenever you pass another vehicle, honk. Get behind it, lay on the horn and keep honking til you are past it. When you approach an intersection, honk the whole way through. If somebody is going too slow for you, honk until they move out of the way. You'll notice two lanes in each direction. That is just a general guideline. Combinations of vehicles 4 across is not unusual. If traffic is slow, drive off the road into the dirt. Beware of cows standing in the road. Also, large herds of goats being shepherded down the highway. If you are on the wrong side of a divided highway, just drive the wrong way until you find a place to turn around. (My favorite sign thus far: an official highway sign that reads Please Do Not Drive in the Wrong Direction.)
Oh man. We took a 4 hour drive to Agra today. We had a hired van and driver. Ritu quite accurately compared it to riding on Harry Potter's Knight Bus. The sights were amazing and overwhelming and it's a miracle that we lived to tell about it. A note about the honking: Many of the trucks have "Horn Please" painted on the rear bumper. I guess they have limited visibility and they want to make sure they know you are there. Often it will also say "Use your dippers at night". That means to flash your high beams. Despite all the honking and swerving, the drivers are very good-natured. There is no swearing or angry outbursts. That's just how you navigate the traffic in India.
After a few hours, the sights on the road are so unpredictable that you stop being surprised by them. A woman holding a baby while riding side-saddle on the back of a motorbike? Why not. A man standing on the highway median with a monkey on a leash in one hand and a bear cub on a leash in the other? But of course. Men standing on the edge of the road peeing? Ok, that one got old pretty fast.