In this lecture, we will go through the foundations of good direct restorative treatments. Rubber dam isolation will cover how to effectively use this technique to improve not only the outcome of your restorations but also comfort. Main isolation methods will be discussed and simple workflows presented, that could be easily implemented in daily practice. Preparation will cover the workflow to safely open up a cavity, discuss the current opinion of dentin preparation, and cover the air abrasion effect on our restorations. Matrixing will discuss various class II problems we encounter every day, presenting a structured workflow and decision-making process in matrix choice.