I've tried to do the blurry before but when I adjust the shutter speed the picture gets all off. Then I mess with the aperature and keep playing with it and then umm its too late and I have nothing to take pictures of. I guess it just takes some practice.
Yeah it takes some practice. Just go out to a busy intersection. If your shooting canon just set your camera to Av. Adjust your shutter speed to around 1/60. If the picture is coming out blurry bump your shutter speed up.