The 5-0-5 and 5-10 scales and many others have and adjustable foot at one end. With nothing but the pan on the scale set the weight adjustments to all zeros. Then adjust the foot to bring the pointer to the center of the scale. Good scales can be effected by air movement, so block or shut off air/furnace vents and fans until you have still air in the scale's area.

A good beam scale is much faster than a digital scale, I currently have 4 beam scales and 2 digital! (and several powder drops)

Ivan