Mass loss plays a crucial role in the lives of massive stars, especially as the star leaves the main sequence and evolves all the way to the red supergiant (RSG) phase. Despite its importance, the physical processes that trigger mass loss events in RSGs are still not well understood. In this talk, I will introduce our new method to reproduce the atmospheric extensions of these cool evolved stars, where mass-loss events take place. I will also discuss the accuracy of our models when comparing the spectral energy distributions (SEDs) and interferometric visibilities with newly obtained VLTI/GRAVITY and MATISSE observations. This new methodology represents a step forward in modelling the winds of cool evolved stars.