I draw most extensively, though not exclusively, from the following evidence-based approaches to psychotherapy:
Motivational Interviewing: http://motivationalinterview.org/clinical/principles.html
Acceptance and Commitment Therapy: http://en.wikipedia.org/wiki/Acceptance_and_commitment_therapy
Mindfulness Based Cognitive Therapy: http://www.mbct.com/
Relational Psychotherapy: http://www.goodtherapy.org/relational-psychotherapy.html