Engineering Admissions Assessment (ENGAA), 1 interview
Questions entirely subject-based (one on mechanics, one on electrics)
Used online resources for practice questions; Revised A-level content
Completed past papers
Prepare as well as you can for the ENGAA - do all of the past papers and work on managing your time
Remember this advice isn't official. There is no guarantee it will reflect your experience because university applications can change between years. Check the official Cambridge and Oxford websites for more accurate information on this year's application format and the required tests.
Also, someone else's experience may not reflect your own. Most interviews are more like conversations than tests and like, any conversation, they are quite interactive.
Test taken:
Number of interviews: 1
Length of interviews: 30 minutes
Online interview: No
No discussion about personal statement or anything, just two engineering problems.
One mechanical one about the forces acting on an object, and one electrical one about circuits. There was also an at-interview test earlier in the day with ENGAA-style questions, but none of the questions were discussed in the interview.
I looked at i-want-to-study-engineering.org for some practice interview-style questions as well as some others just from googling 'Cambridge Engineering interview questions'.
Apart from having a go at some practice interview questions and revising A-level material I'm not sure there is too much you can do to prepare because the questions that come up could be on anything.
Just go into the interview with an open mind (don't get locked in to one way of thinking about how to answer a question and listen to any suggestions the interviewers make) and try to be as calm as you can.
You could also go over everything you've written in your personal statement to prepare although my interview didn't ask anything about that.
Did all the ENGAA past and specimen papers as well as
Prepare as well as you can for the ENGAA - do all of the past papers definitely and work on managing your time and choosing which questions to answer to maximise your marks.
For the interview just try to be as relaxed and calm as you can and go into the interview with an open mind (don't get locked into one way of thinking about how to answer a question and listen to any suggestions the interviewers make).
Don't stress too much about preparation as there's only so much you can do.
Explain your thought process as well as you can to the interviewer, practise doing some interview questions found from googling or i-want-to-study-engineering.org and speaking your thought process out loud as you do them to get good at this.