Data visualization is the presentation of data in graphical format. Graphics help us discover and understand patterns in large amounts of quantitative information. They are powerful tools to communicate actionable insights to our stakeholders. We have all dabbled in data visualization and yet even seasoned researchers can violate the principles of effective visualizations. In this presentation, I discuss Tufte’s principles of graphical excellence. These principles guide researchers to focus on the relationships in the data and to avoid chart junk. I walk through these principles using examples and apply the grammar of graphics, a philosophy that maps data to aesthetic elements. This session equips attendees with a quick foundation that above all else shows the data.