Cells polarize by segregating components within the plasma membrane, cortex, and/or cytoplasm along a particular axis. Canonical examples of cell polarity include the apical-basal and/or planar polarity of an epithelial cell, the front-back polarity of a migrating cell, the anterior-posterior polarity of an embryo, and neuronal polarity underlying the formation of axon and dendrites. At the tissue scale, cell-cell coordination of polarity is critical for both tissue structure and the complex morphogenetic movements necessary to form elaborate tissue architectures. Polarity can arise internally, through the amplification of stochastic molecular fluctuations, or under the guidance of external inputs and can be influenced by actomyosin dynamics. For example, cortical polarity effectors can be advected by cortical actin flow to drive their enrichment at one end of a cell. Currently, the origins of polarity and its maintenance are actively studied in a variety of model organisms and cell culture systems to extract general principles to understand how polarity is disrupted in disease. The goal of this collection is to compile a centralized source of techniques to image, manipulate, and quantify polarity across diverse experimental systems to inspire new experimental approaches and foster collaboration within the community.