I don't know if my method is the best, but it's worked so far: I start by looking over the chart, and making sure I know the major medical diagnoses, medications, past surgeries, etc. That way I don't sound like an idiot. Then (after introducing myself, getting am vitals, etc.) I'll ask if they mind helping me out with an assignment. I explain that I'm supposed to practice interviewing skills and do a physical assessment of whatever we've learned so far. I thank them in advance, and say something about how it never hurts to get a free checkup while they're already here. I ask if they're in pain or uncomfortable, and tell them they can refuse to answer any questions that are too personal, and that if they get too tired, need water, etc. to let me know. I warn them that it will take a "little while." I apologize if I have to interrupt the interview (my instructors have pulled me out to go over assignment, etc. - they only spend maybe 20 minutes on each of our floors). So far this has worked for me to build a pretty good rapport. Also, I use the information I've gotten from the chart, "So, I see here that you had 'stomach surgery'" in 2002, can you tell me what that was for?" so they know I'm not coming in unprepared. Last week, my devout Jehovah's Witness was comfortable enough to tell me that she tried drugs in college, and her actual number of past sexual partners. I start as early as I can - hopefully their visitors aren't there 24/7 so I can get some alone time.
One thing I need help with is how to ask the sexual/drug/etc. questions with family/SO in the room - do I ask someone's spouse, or kid who flew in from wherever, to leave to room just so I can do my homework? And will anyone answer those honestly with family in earshot? It takes so long, and our clinical time is so short this semester, that it doesn't seem right to ask someone's family to leave when maybe they only have the morning off from work (and we're off the floor at 12).