We discuss the effects of selected mixing processes on bimolecular kinetics, and pay special attention to situations involving motion on different mesoscopic scales. We focus on hydrodynamic flow mixing, both within idealized models based on shear and dilatation transformations, as well as through synthetic laminar and turbulent flows. We highlight the Le´vy-walk approach for describing phenomenologically mixing, and also Le´vy-flights, which can be used to mimic conformational mixing for polymers in dilute solutions.