My dictionary gives the meaning of 好自为之 as "look out for yourself". This is a positive thing you might say out of genuine concern for another person, and I think this was also the case with the original meaning for 好自为之.
However, when investigating this, I discovered that many people (mis)use it to mean something negative. Under this usage (I think), you would say it to someone whose actions you disagree with and it conveys an unwillingness to take their side or take responsibility for their (bad) decisions.
Am I understanding this right? If so, what would be an idiomatic English translation of this negative meaning?
(Note: I'm not asking which meaning is proper or correct. I'm also not asking about which meaning is more common in your personal experience, but that is also useful information.)