As promised...
Training to be an interviewer myself at work has been invaluable in learning to be a better interviewee......
Almost everywhere uses competency based behavioural interviews these days which means they'll ask for specific examples and drill down into your initial answer to get at exactly how you behaved in the situation to see if there's evidence of you having a competency (or two). If you give generalisations ("I always..." or "I usually..."), or if you say "we" a lot, they will struggle to find the evidence they need to pass you.
Most specific examples you prepare will be good evidence for more than one competency so don't be afraid to use them more than once, just re-focus them based on what competency you think the question is trying to find evidence for..... this is often quite straightforward in that they may say "tell me about a time you worked in a team", but there will be a competence framework sat behind the "teamwork" competency that they're checking off - this will explain what this means in more detail and gives examples of what constitutes good performance that they should look for in your answer.
Many companies frameworks will be the similar - teamwork will always be one of them as will communication, maybe leadership. See if your work has one (or if at Uni, see if the careers office has some examples). One competency I've only ever seen for ATC, other than "aviation focus", is "tenancity". (After finding out what it meant) I prepared a good example - i.e. about getting injured when training for a triathlon last year but digging in, doing lots of recovery work etc and still managing to compete and set a new PB for the bike split. Few things about this - what I took to be "the tenancity question" didn't mention the word, but I'm still pretty sure that's what it was. Having a positive outcome at the end of the example to prove why your actions were the right thing to solve that situation is good. I wouldn't be scared of using non-workplace examples although have some work stuff in there if you can.
Some examples of the technical questions:
3 pictures of airfields seen from above with an apron and runway, one where they're directly connected so looks like a podium, one where there are taxiways between them connecting to the two ends of the runway, and one where one taxi-way connects to one end and the other connects to the middle. Where would you want to work? How could you make that design better?
What would you have done from a ground / approach point of view if on duty when the 777 crashed. In what order?
One light, one medium, one heavy all same distance from aerodrome want to land - what order do you put them in and why?
Think I gave decent answers to these but I won't say here (I may have been wrong!, and gives you a chance to practice)
Hope some of this has helped,
Cheers