1. Working hard. Expect to stay late and don't fill your evenings with social plans, particularly during the first job when you are finding your feet. You will learn faster and become better at the job the more hours you put in, at least initially. Try to get to know your patients (and their relatives) well as this will make the job more interesting and remind you why you are there... *
2. Manners. Smile and be unfailingly polite to patients, nurses, specialty doctors, receptionists, consultants, etc. You can be an absolutely awful doctor but do extremely well if people enjoy working with you. *
3. Getting the balance right. During normal work hours, your job is to write down what your boss says and find a way to action his/her plan. Outside of normal hours, you will feel as if the weight of the world is on your shoulders but it really isn't. Your job is to see the patient, find out what is going on (history, examination, charts), and then call someone else for a plan. By all means design a plan in your mind beforehand but, in my view, FY1s shouldn't be doing much clinical decision making, and certainly not in their first job. *
You will learn everything else you need (clinical knowledge, practical skills, etc) with time. All you need to do in the meantime is work hard, smile, then call the boss... ;-)