The experiences you gain in both your professional and extra-curricular careers will always be of interest to HSF. However, the candidates that stand out (certainly in the application and assessment centres) are often those that have taken the time to reflect upon things like: the type of skills they developed during an internship, the benefits of learning a foreign language or the experience they gained from volunteering for an organisation and, crucially, how this can all be applied and beneficial to a career in law at HSF.
There is no one thing that can be prescribed. I, for instance, recall discussing my involvement in various sporting teams at University during my assessment centre. It is an exercise of considering which skills and experiences may be of value to a career in law and a firm such as HSF (and this is a broad list), and then looking at your own interests and skill set and going from there.
Thank you for your feedback!