Yes – by the time it came to my last vacation scheme I had a decent sense of how to convert. If you’ve got to the vacation scheme you’re not far off and often it’s about not messing things up rather than having to be perfect – so I’d actually say don’t try too hard to stand out and you will.
Be interested/enthusiastic about the work and ask thoughtful questions when it’s appropriate. Be sincere and a nice person to the other interns (even if others are trying to be competitive)/secretaries/trainees etc. Show you’ve taken feedback on board. Manage expectations if you’ve been given too much work, it’s much better to do less work of a higher quality than trying to work for everyone. There’s a lot more detail I could give and happy to expand if needed but generally these are the kind of qualities you need.