I would probably start with a spline tracing the shapes in plan view (top view), then extrude, convert to editable poly, add subdivision so that you get lots of faces, then start manipulating the face edges to create creeases and valleys. Another method is to create spline cages for each component by tracing out the shape in longitudinal and cross sections... more painful and may not give the right results for some shapes.
You can also try the push pull paint options on an editable poly object after creating the geometry using the first method above.
I'd be interested to hear of other's opinions to see if there is a faster way.