A week before
Start with the documents the interviewers have already seen. Read your application closely and note the choices, assumptions or gaps you may need to explain. Review your PhD CV at the same time so that you can spot and resolve any inconsistency before the interview.
PhD researchers commonly review and synthesise literature, conduct fieldwork to acquire data where relevant, and draft reports or a thesis. Use those activities only as prompts for reviewing your own experience; do not claim work you have not done. For postgraduate research students, a skills self-assessment can identify existing skills, baseline skills and development needs.
Prepare brief notes instead of a script. For each example, write down the context, what you personally did, your reasoning, the result and what you learnt. Practise aloud and cut any detail that hides your main point.
The day before
Re-read the invitation and confirm the time, location or joining instructions. If your interview is remote, test the platform, camera, microphone and internet connection. Keep any permitted notes short enough to scan without losing track of the conversation.
Choose questions whose answers will help you assess the programme. At one UK institution, the interview is a two-way exchange in which the applicant can learn about the department and its support, so questions on those subjects suit that particular setting.
On the day
Give yourself enough time to settle before the interview. Listen to the whole question, pause if you need to think and ask for clarification if the wording is unclear. Answer the point asked, keep your examples truthful and distinguish your contribution from work done by other people.