Recent upsurge in droplet-based microfluidic research is driven by the potential application of drops as biochemical microreactors. These applications require reliable control over the droplet generation process, size and droplet traffic. Here we present electrowetting and pulsed hydrodynamic pressure based actuation of single droplets that allows programmable control over drop generation and size. We will also discuss the power of a fluidic comparator to measure hydrodynamic resistance of single droplets that could provide insights into controlling droplet traffic to build self-organizing passively driven discrete microfluidic systems.