Know when to refine, when to refactor and when to refrain

Chris J Davis in Lessons for the Newly Minted:

As you can clearly see, when you have tight deadlines, and mountains of work, refactoring existing code that works is highly unadvisable. As a developer you must make strategic decisions about where your time is spent, and this must be informed and balanced by the needs of the company. Should you strive to craft breathtakingly beautiful code? Yes, but not at the expense of the overall velocity of your development schedule. Sometimes good enough is beautiful. Amen to that.