How do I make the most of an internship?

First of all you'll have to accept that there is no guaranteed way to ensure that good performance leads to a graduate offer.
However there are a few things or tips that might help you to make a good impression.
1) Be a good listener.
2) Don't be a yes man. Learn to debate in a way that doesn't offend senior management and at the same time doesn't lead to situation where you get overworked.
3) Start slow and build up. A lot of times, we expend a lot of energy in the beginning of a job or internship which simply isn't maintainable. This leads the management to think that your performance is getting worse. On the contrary, if you slowly improve and work smart, it'll give the impression that you continuously are improving.
4) When disagreeing with your seniors use 'and' instead of 'but' when countering their opinions and build on that.
5) Be punctual.
6) Make sure that the boss of your boss knows what tasks you've performed for your boss. Otherwise in the eyes of upper management, your immediate boss will most likely take the credit for it.
7) Learn to handle criticism.
8) Work Smart.
9) Hope for the best.

Good luck to you mate

First of all you'll have to accept that there is no guaranteed way to ensure that good performance leads to a graduate offer.
However there are a few things or tips that might help you to make a good impression.
1) Be a good listener.
2) Don't be a yes man. Learn to debate in a way that doesn't offend senior management and at the same time doesn't lead to situation where you get overworked.
3) Start slow and build up. A lot of times, we expend a lot of energy in the beginning of a job or internship which simply isn't maintainable. This leads the management to think that your performance is getting worse. On the contrary, if you slowly improve and work smart, it'll give the impression that you continuously are improving.
4) When disagreeing with your seniors use 'and' instead of 'but' when countering their opinions and build on that.
5) Be punctual.
6) Make sure that the boss of your boss knows what tasks you've performed for your boss. Otherwise in the eyes of upper management, your immediate boss will most likely take the credit for it.
7) Learn to handle criticism.
8) Work Smart.
9) Hope for the best.

Good luck to you mate

I really appreciated your advice! Do you have any further tips for effective networking? I have a networking event scheduled on my first day and I'm a bit worried I might say the wrong thing

Make your words count. Listen more and talk less. Observe a person, with some time you'll be able to read them more accurately.
Making connections and networking is all about seeing value in a professional relationship. If you display behaviour that signals to the other person that you can be a valuable asset professionally in any capacity, they'll hold on to you. Just try and enjoy your time, don't force things unnecessarily. Focus on improving your skills set and eventually it'll start reflecting in the connections you make.

Thank you again! Sometimes I feel so stupid when I ask questions relating to networking and I genuinely miss speaking to people normally. The part where you mentioned to not force things was great advice!