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

Refactoring without Unit Test is dangerous. Always have unit test. If you change something without having good testing you might be safe for some portion of the code but something elsewhere might not have the same behavior. With Unit Testing you protect any change.

Refactoring other code is fine too but the extreme is not. It's normal that someone else do not program like you do. It's not "kind" to change stuff because you would have did it in the other way. Just refactoring if it's really necessary.