Here we discuss macroemulsions stabilized by interfacial colloidal films, in terms of the basic processes of colloid nucleation, colloid flocculation, and assembly in interfacial films. By monitoring the droplet-diameter, we present the effect of a variety of surfactants, additives, and organic solvents, as well as the amount of the colloid, and that of the continuous and the dispersed liquid phases. A quantitative analysis explains the experimental results and enables us to estimate the film thickness and the flee size. A modified hydrophilic/lyophilic balance scale accounts for the role of the surfactants. It is demonstrated that monitoring the droplet size on the submillimeter scale is a powerful tool in the investigation of colloid processes on the nanometer scale and colloid flocculation in the micrometer and submicrometer scales.