Kubla Cubed User Manual
When defining bulk earthworks it is possible to utilise all the element types to create the proposed topography or it is possible to use just use one. The definition of bulk earthworks elevations usually requires quite a bit more thought and planning than for instance the existing, strip or demolition phases which can be quite straight forward.
In regard to the best approach it often depends on what data you have in your site plan. If you have a set of contour lines defining smooth terrain it would be best to use a Feature Surface and use contour lines. However if you have a series of terraced areas than a number of platforms might be appropriate. For warehouse foundation with a number of ramps you could use some platforms and slope elements or define the whole thing in a feature surface with break-lines.