Part of our research as players should be done, I think, reading and investigating about the life of composers, guitar makers, interpreters... to know who they were, what they thought about life and music and the problematics and challenges they had to deal in their existence. As I always said to my students, they're our best friends. Their are walking beside us for our entire life. So, don't spend your daily work only playing. To read some books can make your vision of a piece more deep and intense, on stage and teaching!