Pretty straightforward process. We opted for a really early interview in hopes of finishing early but I just forgot that there was a visa processing fee that has to be paid on the day of the interview (or maybe we were unaware that there was a visa processing fee). Got to the 1st and 2nd steps fairly quickly but when I got to the CO, she told me that she can't continue with the interview until I pay. She was very understanding, though, what she did was place my interview on hold up until 10am that day so I quickly phoned my husband and father-in-law to wire me some money and then I had to run around the area for a place I could withdraw the money from.
Whew.
So I got that done. Paid the fee and returned to the window I was originally assigned, carried on with the interview. She asked some straightforward questions and asked for some pictures and then "We will mail your passport with your visa. Congratulations."