In another of the excellent short training videos from the National Shooting Sports Foundation, cowboy action shooter Jim Finch aka Long Hunter shows how to use your lower body effectively to increase both speed and accuracy.
While Jim is discussing this in the context of a SASS competition, I think his technique is transferable to other competitions like IDPA. More importantly, I could see this as being transferable to defensive situations where you face multiple attackers and no effective cover or concealment. While moving may be preferable, it isn’t always possible.