Also (and this might vary by professor), but don't forget to give the arguments on BOTH sides before coming to your conclusion. Particularly in contracts, there are a lot of areas where the answer is not clear-cut. It relies on standards such as "good faith" and "substantially impair." Play around with the facts in the case and argue both sides. First take the plaintiff's side and argue how the defendant's action was not in good faith. Then take the defendant's side and argue how it was in good faith. THEN come to your conclusion. All this could do is get you more points.