As stated know your knowledge and get it wire tight. Ask as many questions as you can to anyone you can. I will ask paramedics and nurses for a few minutes after calls and pick their brains on certain things that could have gone differently or new things that I have very little experience with. Try and steer away from all the "what if" questions as this can go a million different ways and doesn't usually end with a clear cut answer in my opinion. My biggest piece of advice from working as an EMT is "chill brah". In my opinion one of our main callings as an EMT-B is to treat anxiety. Yes we set up the assessment/treatment with anything and everything in our scope of practice, and also assist higher scopes of practice with their care, but helping to de-stress a patient and preparing them for treatment in a hospital is a huge perk for not only the patient, but yourself and everyone involved with the patient's care.
Arriving on scene to every call of any nature I personally try and get into the mentality that the patient just needs a band aid, no big deal. Let me explain this. I do not stroll on scene and take my time or do anything that would compromise personal safety or patient care, but I do walk on scene calm, cool, prepared, and ready to treat the patient. Walk on scene like your the 7/11 guy with a BP cuff and treat the patient like a person and not a number and you will get such an entirely different attitude from patients, medics, nurses, and doctors than you would have thought. Hope that helps some and hope you get the time to put it into practice. Take care and Good Luck!