Multiphase flows, involving droplets and/or particles, are ubiquitous in nature and industrial applications, ranging from oil recovery, additive manufacturing, to drug delivery. The major theme in our group is to utilize experimental measurements in multiphase flow systems to unveil fundamental controlling physics and to develop new strategies for applications in energy, environment, to healthcare. In this talk, I will discuss two examples involving droplets and particles. The first topic focuses on the migration of colloidal particles driven by solute concentration gradient, known as diffusiophoresis. Particles can be delivered into dead-end pores via diffusiophoresis, which are otherwise hard or slow to achieve.  In addition, utilizing the interaction between solute-emitting particles and surface charge heterogeneity, I will demonstrate a strategy to pattern the particle distribution and assemble particles, which can be exploited in applications such as photonic crystals. In the second part, I will discuss the dynamics of drop impact on liquid films, especially with complex fluids. I will demonstrate how the complex interplay among material properties and impact conditions orchestrate various impact outcomes and discuss scaling analysis of the regime diagram. Our experimental observations and scaling analyses have led to new insights into optimizing operating conditions in various applications such as additive manufacturing.