Abstract: Gamma-ray bursts (GRBs) both long and short release a jet of plasma into their environment. The radiation from these jets will evolve from prompt stage to afterglow, and the jet evolves from ultra-relativistic flow to eventually non-relativistic. Recent observed features of interest in GRB astrophysics include Compton upscattering, co-detection with a gravitational wave event (and its implications for the jet geometry) and observations of the centroid motion and image size of GRB jets. I will discuss the methods and results from our research group and collaborators in modelling of afterglows. Using a range of approaches, including moving-mesh hydrodynamics and a kinetic-equation solver for the radiating electron population in the plasma, we are able to make predictions and interpret observations. Further progress can be made by utilitizing the scale-invariance inherent in power-law synchrotron emission and hydrodynamics, revealing how emission from arbitrary jet models depend on explosion energy and environment. This presentation will include a pedagogical element for those not working on GRBs themselves.