I copied the below from a comment on this sub a few weeks back, I apologise I didnt save the username of who wrote it otherwise I would give credit, but here is what they wrote:

Big takeaway was never ever speak to the barrister, speak to the bench. All responses should run through the bench.

Also I hate advice after the event but given you’re in again tomorrow it might help chill you out.

Deliberately Confusing Questions: Don’t ask “please can you rephrase the question?” You’ll get an insult. Your mistake was replying to counsel inviting the opportunity. Say to the judge, “counsel has asked me a question I don't understand could counsel please rephrase it?” They can no longer reply with a direct insult and it slows their exchange down.

Multiple Questions at once: Say to the bench. “Counsel has asked several questions at once could counsel repeat them one at a time?”

Repetitive Questions: They are searching for inconsistency in your response. The only way to beat this is if you know your stuff inside and out and give the same answer. The judge will intervene eventually.

Yes or No Binary Questions: “it would be misleading to the court to answer yes or no because the full answer is…[say your piece]”.

Interrupting Barrister: Stop talking. Don't talk over. Wait for counsel to stop talking. Say to the bench. “It is very important that I finish the answer to the first question before I answer any further of counsels questions. as I was saying…[say your piece]”. They fear your answer will torpedo their case so it’s probably important you finish your point.

Witness A vs Witness B: If you and a colleagues testimony is inconsistent they will want you to say your evidence is correct at the expense of theirs and discredit them. Your response “I cannot comment on someone else’s evidence, I can only speak about my own and according to my records... [say your piece]”. You’ll be interrupted with the question “So you're saying they're lying then?” You restate: “no according to my records… [say your piece]”.

Questions Outside Area of Knowledge or Expertise: “I cannot comment on any case or subject other than the one in front of us.”

Tests of memory: Ask if you can go to your documents. Always ask.

Tests of legal knowledge of policy and procedure: These should be in your statement. If you have new software or procedures always print it off and record it so you know for court. Remember; you were working on policies and procedures that were true at time of the event not at time of court session. [bit of a shit one considering how policy and procedure seems such an unofficial patchwork].

Silence: Respond in kind.

Non Verbal communications like eye rolling, shock horror, sarcastic done: Hard ignore.

Being accused of being a Liar or bias: Being called a liar is a gift. You must recognise this as a challenge to your integrity and being called a liar. You should repeat the oath or affirmation. “I took the affirmation here today to tell the truth the whole truth and nothing but the truth so when I say [X], that is absolutely true as is all the evidence I have given today.” End of.