I had a phone interview 3 weeks prior to going to Tulsa OK. 20 other people from all over the US where there. My only advice to you is do your research and ask questions. Don't look bored. Its not hard and its very casual. The 2nd day after power point and some group exercises was a tour of a training facility. Ask questions, you will get an offer. Then you have your exit interview. Not necessarily but gives you some one on one.It's a good idea after a long day you have drinks at the bar. Have one and talk to the recruiters. Then excuse yourself and get a good nights rest. I got home late in the night and when I woke up I had an offer. Waiting for background check, driving and drug hair sample.