After introductions you tell about yourself, your job experiences and why you think you are a good fit for the job you are applying for. Some companies have a 100 percent smoke free environment and that means even at home so make sure you do not smoke cigarettes( even at home) if you intend on being hired. They do nicotine testing.( the contractors) not temp services. How many days you have been late or missed work will be in question. Also talk about the good experiences you have had with past employers. Have good reliable references.