Interrogatories are written questions the other side has to answer under oath during discovery. They're a core discovery tool — and also one of the easiest to waste, since vague questions invite vague, technically-compliant answers.
Ask one thing at a time
Compound questions ('describe the accident and all resulting injuries and treatment') often get combined, evasive answers. Splitting them into distinct, single-subject questions makes it harder to answer around the point.
Define terms so answers can't dodge on semantics
Precisely defining key terms used throughout the interrogatories closes off one of the most common evasive-answer tactics: technical, narrow readings of ambiguous language.
Watch the numeric limits
Most jurisdictions cap the number of interrogatories allowed without leave of court, often counting subparts toward the total — drafting efficiently, without wasting the limit on redundant questions, matters as much as the wording itself.
Follow up on evasive or incomplete answers
An answer that doesn't actually respond to the question isn't the end of the road — a follow-up meet-and-confer, and if necessary a motion to compel, is often needed to get the substantive answer the question was actually asking for.