Answer the question you were asked. Then stop talking.
Volunteering extra material under pressure is one of the most common ways people damage their own case in the room.
Practise the pause
A brief pause before answering is unremarkable. A fast, defensive answer to a hard question is memorable, and not in your favour.
"I don't know" is a real answer
So is "I'd need to check the record."
Both are far better than a guess that turns out to be wrong.
Know your documents
You should be able to find any date or figure you've relied on without hesitation. This is where months of careful filing pay off directly.
Rehearse the ones you dread
Out loud, with someone else asking. Your own list of weak points is the preparation list.
Not just in court
The same applies to meetings with any professional involved, such as a welfare officer or evaluator. Answer what was asked, and resist turning it into an argument about the other parent.
Over-advocacy in those settings tends to read as a red flag rather than a strength. That's counterintuitive, and worth knowing before you're sitting in one.
Credibility is built by precision, not by having an answer for everything.
How hearings work, and who asks questions, varies a great deal between courts and countries. Ask your lawyer what to expect in yours.
General information, not legal advice. Court process differs between countries and regions; check anything that matters to your case with a qualified lawyer where you live.
Chapter 23 of the workbook covers preparing to give oral evidence, and Chapter 24 the days just before. Worksheet L, the pre-hearing checklist, includes practising your hardest questions out loud.
See the workbook & spreadsheet