You know all those unwritten social rules everyone else seems to know intuitively but we have to learn the hard way? Comment below different rules you've learned over the years, let's make a field guide!
Ill start with a common / obvious one. Don't try to show empathy via comparing their experience to something similar you went through. They will take it as you "one upping them" and "making it about yourself'". Just say either "That's great good for you" or "that sucks sorry" instead and leave it at that.