The Impeachment process is way to difficult and political to be used in most cases when a President has overstepped their constitutional authority or committed a criminal activity. This creates an atmosphere where the President might feel that they could get away with almost anything as long as their party is in control and/or the media is on their side. Therefore other lesser punishments must be available to deter future actions by our Commander in Chief. Here are a few remedies (below) I believe the Congress should enact if these cases do arise .
(1) An action that the President has taken can be stayed if a majority in the congress feel it is unconstitutional and immediately taken to a Federal Court for Review.
(2) If the Federal Court deems the act Unconstitutional the President can be personally fined for his/her actions. This decision would of course be subject to immediate appeal
(3) If the President refuses to agree to the decision of the court or continues to act in further ways that go over his boundary of power he/she can have this particular power removed from their authority and be given to a third party appointment by the court to administer.
(4) The courts can also hold proceedings of impeachment which although would not subject the President to such action would give credence to any action the House and Senate might take up if they deem necessary.