Painting Weights Process
Select all the joints you plan to weight to, then select the "sock puppet" mesh. Go to Skin > Smooth Skin > Option Box and use these settings (Fig.21).
Fig. 21 - Initial smooth skin settings
Calisthenics (Range of Motion) on the Rig
Having a set range of motion on a character will allow you to quickly scrub the timeline and see the effects of your weighting adjustments.
Fig. 22 - Range of motion movie
Switch to the FK controls if the character is already rigged or if not then key directly on the bind joints:
• Left fingers
• Left wrist, elbow, shoulder, clavicle, stretch long, common poses (arm in front)
• Head/neck, spine from top to bottom
• Left hip, knee, ankle, toe, stretch long, common poses (toe raised, seated position)
Hide non-skinning joints, rig elements (locators, IK Handles) and non-skinning meshes to make the viewport as clean as possible.
Next show joints and geo in the viewport (Show > None; Show > Joints; Show > Polygons etc). Then x-ray joints in the viewport (Shading > X-Ray Joints).
Set the joint color to red for easy viewing of joints, since purple on black can be difficult (mel script):
//Joint Color Red
displayColor -dormant "fkJoints" 13;
//To return to Default Joint Color
displayColor -dormant "fkJoints" 8;
Painting Weights - Process
Open the Paint Weight Brush and keep the options open (Skin > Edit Smooth Skin > Paint Skin Weights Tool > Option Box).
From here, you can either flood the mesh to the root and paint from scratch, or paint atop the default results. Since you'll be adjusting all the verts anyways, it's really about how much time you have at the moment. If time is short, you can paint atop the default values to hit the main areas to get the character to animation sooner, or you can flood to the root joint and go through each section with much more precision.
Set Paint Operation to Add, Opacity to .4 and Value to .25. Right-click on the left thumb tip joint, and select "Select Influence' in the Marking menu. Then paint the verts for that joint (Fig.23).
Fig. 23 - Weights before and after