Abstract: This talk is based on two works one with Ivan Moyano and another with Helge Dietert. I will discuss the theory of hypocoercivity which deals with convergence to equilibrium for linear kinetic equations involving both transport of particles and a collision term affecting their velocity. This theory becomes more complicated when the rate at which collisions happen depends on where you are in the space. I will talk about works that show how to bound the rate of convergence to equilibrium in some specific cases, and also about our new project (including the completed work with Helge) about how to choose the collision rate to maximise the speed of convergence to equilibrium.