This book provides a general, technical description of fine-tuning piano unisons, based on the contemporary acoustical theory, which is outlined in the accompanying volume The Physics of Piano Unisons (Volume 1 of this series). The content of this book is aimed at anyone with a technical interest in the subject, including tuning students and professionals. The discussion can be related to practice, and its only mathematical content is graphs illustrating acoustical behaviour. For a more comprehensive treatment of all aspects of piano tuning and its theory, please consult Theory and Practice of Piano Tuning by the same author.