O1 visa interview

[Alfa16]

Hi all,
I have my O1 (Science & Tech) petition approved and have visa interview next week. My wife will have O3 visa interview. I heard it can be tricky and also heard stories of getting rejection. Can someone, who went through this process share their experience, what to expect at interview and how to tackle those questions, any tips and Do's and Don't will be appreciated.

[o1visaapplicant]

How did your interview go? Did you get a 221 g? If so, how long did it take to get resolution on the 221 g?