I don't know about other folks but the method I learned and used was to put the Johnson bar near the corner and take off trying not to exceed the speed limit. I have the Fireman give it extra oil, but not too much. To me some smoke, but not a smudge pot looks good. It helps if it is done in the early hours of the morning on a cold day, then the combination of unburned oil and steam is most dramatic.
Going down hill, I first start coasting, then apply a little brakes and begin opening the throttle. As I continue to open the throttle and let her work harder, if necessary I apply a little more brake. Once again I have the Fireman make smoke, but don't coat the trees with oil.
Jim's right, excess sanding means more cleaning in the smokebox and firebox. While running normal (no photo specials) I find with a clean stack we seldom need to sand the flues.
dan