Soft vs. Hard Edges

I've recently been re-exploring the advantages of contrasting soft areas with hard edges.  Mixing the colors on the paper rather than homogenizing them on the palette first makes for a more glowing effect and, of course, a softer look.  Soft underpainting makes a good foundation for harder edged shapes to be placed on top. 

Of course, you need to think which areas make using soft edges feasible.  A soft-edged rock doesn't register as a hard surface.  On the other hand, hard edges on clouds defy their soft nature.  Large areas also provide an opportunity to give an out-of-focus look that provides relief from the hard edged focal subjects.