The bar examiners see every candidate as potentially practicing unsupervised. Find out what the practitioner's problem is, the law practice problem to be solved. Act like a practitioner, not a law student. Find out the client's question first. Analyze the interrogatory and divide it into its component questions.
Interrogatories vary from state to state, but there are patterns.
Make sure, first, not to skip any possible parties. Don't forget the United States Postal Service as a party. Second, be careful to set out the basic principles of law underlying each cause of action of each party. Pay particular attention to remedies. List the major principles of law needed to answer each part of the question and write the answer by applying those rules to the facts.