I didn't do any paid interview prep but my experience was similar to Red Baron. I used my laptop to video my responses and watch my body language. I went through my logbook and pulled out the various scenarios/events I had written down in it over time, from kicking passengers off to first week of CA seat to an engine failure. I didn't even use note cards I was too cheap to even buy those, I ripped up paper into squares and wrote down sample questions and randomized them.

Going into it I was fairly confident and had a good amount of stories that could work for most any type of question even if it wasn't exactly asked like the gauge said. I had a few that were similar but most were a little different.