"There are three things extremely hard: steel, a diamond, and to know one's self." - Benjamin Franklin
Stop every now and then to evaluate how you are doing. Explore and assess the success of your interactions with others. Ask for feedback from those around you and identify areas that you need or would like to improve on.
Know you strengths and document your achievements as you go along. This can really help when you need to write job applications or answer interview questions for academic and other career trajectories.
Identify areas that you need to develop and look for training or experience opportunities. Talk with your supervisor and other college support services.
Remember be fair and kind to yourself. If you judge yourself too harshly you can risk developing ‘imposter syndrome’. Caltech describes imposter syndrome very well on their website.