ball endmill 3d

Hi, happy new year! i have used master5cnc to engrave pictures, always used a fine tipped angled cutter. i want to try some engraving of pictures using ball end mills, or taper side ball end mills. typical sizes are 1/4 inch, 1/8 or 1/16 inch cutters. I have no idea where to start on step-over setting. cul brian f.