When painting either digitally or traditionally, I only use a very small range of brushes for my images. In Adobe Photoshop I usually render hi-lights and details with the following:
hard edged brush, 1% SPACING (for super smooth lines) size 10-20
soft edged brush, size 30-100
The soft edge brush is also useful for softening the entry and exit points of hard light.
For Photography, I shoot with a Canon 500D and carry 2 additional cheaper cameras for backup.
When painting traditionally, I usually use imitation sable, sizes 1 & 4.