My VI was on 10th of Jul 2012. 7:45 AM slot. My Token number was 368, so I had enough time to observe how other VIs were going on.
The rejection rate on that day could be around 50% to 60% but most of the rejections were very obvious. I could see that most of the people with good confidence and clear intentions (as I heard in there answers) were getting visa approved. And then my Token flashed on the counter number 26.

He was a American guy in his early 30s. I was observing him, he was doing his job very carefully and the rejections he did were quite obvious. There was no one when I went to the counter.
I had a big smile when I approached him and passed him passport and i20 before he asked me to.

Me : Good Morning !!
VO : Good Morning, Long Beach huh (seeing my i20)

VO : Why Masters?
Me : I did my undergrad. in IT which was less technical and during 4 years of my profession life I have realized that I was missing technical skills which I observed in my seniors at work and thought Masters could be a chance to learn more about computers and posses such technical skills. (he seemed to be convinced with my answer)

VO : Which colleges did you apply to?
Me : CSULB, UD, SDSU and SJSU (Full forms)

VO : 4 Year !! Where did you work and what was the work?
Me : I have worked at BMC Software for 3.8 yrs and since last dec I am working with Cognizant. I was product developer in both the companies.

VO : Coding? (with gesture of typing on keyboard)
Me : (With smile) Yes, Coding (with gesture of typing on keyboard)

VO : Who is funding you Education?
Me : I have my savings and my father has his savings which I will be using for my education, My father is Teacher.

VO : Ok, I am approving your Visa, It will be delivered to you in 2-3 days.
Me : (I was so surprised and couldn't believe what what I heard, so just to reconfirm I asked him) Is my visa approved sir?
VO : Yes (with a big Smile)
Me : Thank you sir !! You made my day.. (I was feeling so grateful to him; I wanted to keep on saying thank you.... )

Yes... with these very few questions asked and no document checked my visa was approved. Perhaps luckiest day in my life.

- Keep answers "short and sweet"
- Try to be confident and speak with clear pronunciations.
- Smile adds some charm and makes conversation pleasant.
- If you could try to be little funny (without overstepping the seriousness of the process) it can help, hopefully this would humor the VO.

All the best for your VI !!