I generally sit down at an SGI, start GRASP, generate 3 surfaces (electrostatic, hydrophobic, and surface curvature), write them out, and do the rest in Povscript+.

Here is what I do while working in Grasp.

Build the surface and electrostatic potential.
On our system this is a macro (Alt-s).  
This is the macro.
    Macro Name: Surf_Charge_PB_Interpolate
    Define: Alt S
    menu :GRASP | Build
    menu :This Structure.. | Molecular Surface
    menu :Which Atoms | All Atoms
    menu :GRASP | Read
    menu :Read Submenu | Radius/Charge File (+Assign)
    menu :Charge and Size File List | full.crg
    menu :GRASP | Calculate
    menu :Calculate Submenu | New Potential Map
    menu :GRASP | Calculate
    menu :Calculate Submenu | Pot. via Map at Surfaces/Atoms
    menu :Which Atoms | All Atoms
    menu :What Surface | All Surfaces
    Macro End

Then do the following to add curvature and hydrophobicity:
Calculate>Surface Curvature (+Display)>All Surfaces>All Atoms
Calculate>Area of a Surface/Molecule>Molecule>Accessible Area>All Atoms
Calculate>Simple Property Math>Atom Properties>Enter String>r=hyd>
  Op(Array)=Scalar>Sum of Values > Accessible area
Calculate>Simple Property Math>Atom Properties>Enter String>r=pol>
  Op(Array)=Scalar>Sum of Values > Accessible area
Calculate>Simple Property Math>Map Atom Value to Surface>All Surfaces>
  All Atoms > Accessible area > general property 1
Write>Grasp Surface File>Let me enter it>Absolute Centering: All surfaces

The povscript part is almost trivial

     plot
       window 45;
     slab 70;
     background white;
     
     read mol "pdz1.pdb";
     readsurf id1 "pdz1.srf" potential;
       transform atom *
         by centre position atom *
         by rotation and translations
        ;
     
     set maptype 1;
     set surfrange -10 0 10;
     set mapramp from red to blue through white;
     drawsurf id1;
     end_plot

For hydrophobicity, use readsurf property1.
For curvature, use readsurf curvature (duh)

find good views with OpenGL mode
povscript -gl -in grasp.povs

Images