How should case law be used to answer problem questions?

Case law should be applied to the questions presented in exams using the ILAC method. This stands for Issue, Law, Application, and Conclusion. In short, you identify a factual issue presented by the question. You then briefly explain the law that relates to that issue (citing case names where you can). You then apply the case to the issue, by drawing comparisons between the facts and issues in the case, and those in the question presented to you. Finally you conclude by summing up how a given case applies, and any weaknesses in the argument.
Below is a short example based on a criminal law problem in which an individual supplies drugs to a friend who is killed by them.
Issue - Gross negligence manslaughter by omission (particularly relating to drugs)Law - The general rule is that one cannot be liable for an omission, and that failing to get help after another person overdoses is an omission. (Kennedy) However the case of Evans presents a possible exception to this. Where the supplier (1) remained with the victim after they ingested the drugs, (2) where the supplier realises an overdose has occurred, and (3) where the supplier believes they are responsible for the victim, criminal liability will arise.Application - Evans does not apply to these facts. Whilst the supplier remained with her friend, she was not aware that her friend had overdosed, and therefore the second limb of the test in Evans is not satisfied. Conclusion - The supplier in this case is unlikely to be found liable for manslaughter. However, this is a developing area of law, and Evans has not been confirmed by the Supreme Court.