How to correctly save instance state of Fragments in back stack?

Question

I have found many instances of a similar question on SO but no answer unfortunately meets my requirements.

I have different layouts for portrait and landscape and I

Answer 1

final FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.hide(currentFragment);
ft.add(R.id.content_frame, newFragment.newInstance(context), "Profile");
ft.addToBackStack(null);
ft.commit();