this question mainly aims to understand if you have experiences that show the skills needed to be a good consultant.
A good answer would emphasize:
- Three parts of your CV that you consider most relevant. This may involve working experience, education and extracurricular activities, or more focus on one of these areas, according to your profile. The order is up to you, but ideally you should use recent experiences (eg not something you did 10 years ago).
- The specific description of what you have done
- How such experiences helped you to develop skills that are useful in consulting. This is the selling part you mentioned. Ending the story which such takeaway will let the interviewer perceive you have indeed the characteristics of a good consultant.
You may then conclude saying that such path naturally brought you to be interested in consulting.
In terms of skills to emphasize, potential useful ones include:
- Analytical skills
- Communication skills
- Sales skills
- Ability to interact with C-Levels
- Teamwork skills
- Ability to achieve results under strict deadlines and constraints
The key in all the examples is to be extremely specific. One of the most common mistakes candidates do is to think that they can give a general idea to the interviewer of what they did and that this would be enough. This is rarely the case. To really understand you, the interviewer needs to understand and visualize the experiences you had and he/she cannot do this without specific examples.