Example of good exception handling for vf pages

snippet.cls

public void functionWithDML() {
  try {
    insert listOfStuff;
  } catch(DMLException e1) {
    // do nothing here, page messages are automatically generated
  } catch(Exception e2) {
    // uh-oh, something else happened bad, better show it to the user
    ApexPages.addMessage(
      new ApexPages.Message(
          ApexPages.Severity.ERROR
        , 'Unknown exception while inserting your list of stuff.  Please contact support. Exception: ' + e
      )
    );
  }
}