Situation and/or Task Action (what you did) Result
so think about situations you have encountered in the past and formulate responses based on the above, both professional and personal situations may be appropriate, and some responses may be suitable to a number of different questions if you angle them the right way. have a good google - there are lots of lists of potential questions available to help you prepare. think about what they will be wanting from you in the context of the job (clues will be in the job description), so try to prepare responses which will convey the fact that you have these skills (or the potential to develop them)
If I demobsteate throughtout my application form a certain skill for example communication such as using email etc can I use a more niche.method of communication in line with what might be involved in the job?
I had one of these recently and my biggest bit of advice is to prepare, prepare, prepare. Presumably they will have advised you of the competencies that are required for the job - then you can think of situations where you have demonstrated those competencies (STAR as someone mentioned above).
I didn't prepare enough, and thought the interview went really badly. I struggled to give good examples, partly because I am newish to my career area, and was in a crap job before that didn't give me the chance to try being competent at anything! So I ended up using examples from before I retrained, and they were OK with that, but I did ask first.
Despite the crap interview, I got the job! Not something I want to go through again for a while, though. Have to say I prefer the old-fashioned type of interview. Didn't feel they saw the best of me at all.