How do you refactor?

Question

I was wondering how other developers begin refactoring. What is your first step? How this process (refactoring) differ if you refactor code which is not yours? Do you write

Answer 1

I take crap and make it less crappy. :-)

Seriously. I don't refactor to create new functionality. Refactoring occurs before new stuff. If there are no tests I write tests to make sure that I'm not breaking anything with my refactoring. If there are tests, I use those. If the tests are insufficient, I might write more tests but I would consider this separate from the refactoring and do it first.

The first step for me is to notice that I can abstract something and make it more general (and useful in other places that need the functionality now), or I notice that something is bad and could be better (subjective). I don't refactor to generality without a reason. YAGNI principle applies.

We have the concept of shared ownership so the code is always mine -- I may not have written it, but I don't consider that when refactoring. I may seek to understand things before I decide it needs refactoring if the purpose isn't clear -- although that's almost always a reason to refactor in and of itself.