Almost 90 years after his death, Halsted's principles remain one of the most important creeds for the surgeon. Many of Halsted's principles are tangible and easily recognized. The importance of asepsis is stressed by everyone practising surgery (although not always adhered to as diligently as it should be). Haemostasis (or the lack thereof) is readily evident and demands attention before each surgery is completed and the patient discharged from hospital. Most surgeons understand the need to minimize dead space and take measures to close it…This chapter aims to highlight the most important principles of surgery that have an impact on outcome. It will also provide practical hints as to how better to follow Halsted's principles. The following are addressed: Incision and excision of tissue; Haemostasis; Care and handling of tissue; Closure of tissue planes; The surgical assistant; and Minimizing operative time.