Some college career centers have advisors who can help you prepare with a mock interview.  Take advantage of this service if it’s available.  If mock interview help is not available at your school, sit with a friend or family member (preferably someone with engineering experience) and provide them with a list of potential questions you expect to be asked during your job interview. Invite the mock interviewer to ask their own relevant questions if they think of any. Employers want to see someone who has self-knowledge and a certain degree of passion for engineering.  For instance, you might say, “I am passionate about engineering because I love the creative process, the collaborative lab environment, and the knowledge that my engineering is contributing to a better world.  I’d like to bring that passion to your company.” Be able to describe your career goals in a sentence or two. Read the company’s values and mission statement, and make note of how they resonate with you.  Do some research into what sorts of products the company makes or what sorts of services it provides, and use this information in the interview to explain why you’re interested in working for them. For instance, if you’re applying to be a medical device engineer, you could say, “I believe in your company’s mission of empowering doctors and medical professionals to do their jobs better and, ultimately, save lives.” For instance, when you’re asked about what experiences make a great engineer, don’t talk about the importance of generosity.  Talking too much or rambling will make the interviewers doubt your competency. Be as direct, focused, and concise as possible when answering your interviewer's questions. Your answers should typically be 30 to 90 seconds long. Deliver your answers with confidence.  Speak at a normal pace and an audible volume.  Look your interviewers in the eye and smile as you speak.

Summary:
Do a mock interview with your college advisor or someone you trust. Be prepared to explain why you’ve chosen to become an engineer. Do some background research into the company you’re applying to. Stay focused on the questions you’re asked when answering. Don’t rush your answers or mumble.