Having done a few video interviews and having had good success at that stage (although not after), I thought I would share a few tips that might be of help. I think the key thing to remember is that there is a reason the firm has chosen to do a video interview. Any question asked during that interview could have been asked in the application, and the firm would have received a much stronger and thoughtful answer. What I'm getting at, is that realistically they are not too interested in what you answer, but rather how you answer.
Speak slowly, smile and look directly at the camera. Prepare for likely questions (why law, why firm, describe a time..), and use the time they give you to read over your notes to clear your head and compose yourself, but DO NOT read from them once the camera is rolling. In relation to this, the chances are that you will be asked questions you have not prepared for, and questions that you are thrown by. This is precisely the idea, to completely throw you then record as you either 'sink or swim'. Whatever the question is, relevant examples are key. You are much more likely to come across composed and fluid if you are talking about something you actually did/experienced, rather than listing points or thinking as you go. Some firms may give you the chance to record anything else at the end (I know of at least two firms that do this) - don't neglect this; in the relief to get the VI over with, its easy to bypass this bit, but saying a quick thank you for considering your application, and that you look forward to hearing from them, can go a LONG way. Similarly, if you manage to be calm enough by the end of the last question to add in a 'thank you', then fair play to you (I never have been!). The 'applyshinewin' resource posted above is really useful, even for just gathering examples of questions. However, as many times as you practice (which I can't overstress the importance of), I would ALWAYS recommend doing the practice question the firm (usually) gives in the actual interview. However much you have practiced with Youtube etc., the feeling when actually in the moment, with your business attire on, is definitely different. Use that practice to compose yourself and test small things like lighting and sound. The last thing you want is the recruiter automatically taking a dislike to your video because of poor lighting/background noise/too quiet.
A minute sounds ages to talk with no interruptions, but it's really not. If you have genuine reasons to want to join a firm, you will never get them all across in a minute. Prioritise them, and definitely do not list. If a reason is 'international presence', make sure you have the numbers to hand, rather than saying 'loads of offices everywhere' etc.
Final thing, if there's a chance to say something slightly 'humorous', then go for it. This is dodgy territory, and I am by no means advocating joking through your interview, but it can show the recruiter watching your video that you are relaxed and able to think clearly and coherently enough to even add in extras. To give an example, I know of someone that was asked about teamwork in a VI, and threw in something along the lines of 'a maverick approach will not best suit the needs of the client; this isnt Suits' (I can't remember the precise wording). It was something the recruiters actually highlighted as something they remembered and liked. Remember, this is potentially how you interact with a client, so they want relaxed and coherent.
Hope this helps anyone, and good luck!
