Advice: Accept that you have been certificated by the FAA, meaning you can tell them the right info. However, getting it across to that one student who seems to never hear what you say is something you can't be tested on. There will be plenty of days where you wonder if you are talking to a brick wall, so be ready. The trick is to relax, focus on the real problem, and work on a solution. Also, talk to older instructors (friends or co-workers), you never know when they will have a useful technique or can see a problem you don't.