What's your top tip for doing well at interview?

Having just gone through an interview myself I thought about the job role and the essential criteria and what skills experience I had that matched. I also practised saying out loud some of my proposed answers so I got used to what I wanted to say and how that sounded. I think this is my top tip as it really helped me to sharpen my answers and focus

You may be asked to prepare a presentation or work through an example task beforehand, for you to discuss at the interview. In addition, you'll be asked questions around the job role (as in the advert) and how your existing skills & aptitudes fit into that.

Use Success Profiles. For Experience and Technical, you'll get questions about the criteria from the advert, so think of examples of when you've used those.

For Behaviours, think of examples of when you've demonstrated the behaviours listed in the advert. You can prepare by taking a STAR approach - think about the Situation, Task, Action and Result.

For Strengths, they won't be listed on the advert, because they are assessing your instinctive response to questions about particular traits. You can get information about all the Success Profiles elements on GOV.UK: https://www.gov.uk/government/publications/success-profiles

I'd say to have a look at the success profiles for the behaviours, spend some time thinking of what your examples are, but don't expect to be able to use them as a script, the questions you will get will be slightly different.

Read all available material on Civil Service Jobsite about Strength based questions and Success criteria. Remember the S.T.A.R. process. Answer the question asked with real world examples where possible. Take your time. Absorb what the questioner is asking you.

If you can have a mock interview so someone can test your examples and give feedback
Remember when delivering your examples use 'I' , not 'we' if talking about things that you have done , even if part of the team. The Panel are interested in YOU not anyone else.
As Jim has said make sure you follow S.T.A.R process. It is quite easy sometimes to say the what but not the why we did things