There are different paradigms of programming (for example, functional, imperative, and object-oriented) and styles (for example, compact, verbose, minimalistic, and too clever). Therefore, the candidates for refactoring are different from one person to the other.
There is another way, as opposed to subjectively, of finding candidates for refactoring—objectively. There are many papers investigating how to find candidates for refactoring objectively. This is just an introduction and it is left to the reader to learn more about these techniques.