Just some small things I am considering these days:
- Work with your advisors: not be driven by them, but learn and discuss with them.
- Being a graduate student is about learning what is scientific research, practising how to do research on your own, not by your supervisor.
- Be active and communicative, then you can grasp the chances.
- There is no need to compare yourself with others (you are a unique individual, how can you quantify the difference with another person?!). Thus, doing your own best is the goal. Challenge yourself!