Data visualization is a vital skill for scientists of all disciplines, affording the ability to generate insights about data and communicate those insights to others. In this talk, we will discuss principles for designing effective visualizations that make complex ideas easy to understand. These principles are rooted in innate human perceptual abilities (and limitations) to parse visual features. We will also examine the importance of displaying variation and uncertainty, visualization strategies for highdimensional data, and common pitfalls when using color. After attending the talk, audience members should feel better prepared to design clearer graphics that communicate their intended message. This talk represents a subset of principles in our 2017 invited chapter in the Handbook of Psychophysiology, 4th Edition, Cambridge University Press.