Ron Jeffries, Refactoring — Not on the backlog!
Simples! We take the next feature that we are asked to build, and instead of detouring around all the weeds and bushes, we take the time to clear a path through some of them. Maybe we detour around others. We improve the code where we work, and ignore the code where we don't have to work. We get a nice clean path for some of our work. Odds are, we'll visit this place again: that's how software development works.
Check out his drawings, telling the story of a project evolving from a clear lawn to one overwhelmed with brush. Once your project is overwhelmed with code slowing you down, don’t burn it down. Jeffries says we should instead use whatever work is next to do enabling refactorings to make the project work happens. Since locality is such a strong force in software, it’s likely that refactoring will help the next bit of project work. Repeat several times and a new golden path emerges through your software.
In other words, don’t reach for a new master plan when the effort to change your software goes up. Pave the cow paths through whatever work you’re doing!