Start with the prompt below, and write for as long as you can. Then, review what you have written, and make it as interesting as possible. Look to the post below "Quality Word-Padding" for how to make your writing longer without making it boring or pointless.
"I thought driving in the carpool lane was supposed to be faster," one of my passengers complained. "What's taking so long?"
I didn't reply, because the answer was obvious. Someone had swerved in front of a truck, forcing it to turn abruptly and spill its load of timber all across the road. It didn't bother me that we were delayed, or that at least one of my passengers had more hot air than common sense... What bothered me was that I had seen the car that swerved in front of the truck. After causing this traffic jam, that car's driver sped away, avoiding the consequences of the overpopulation of automobiles idling behind the spilled timber.