There have been a lot of good responses in this thread, and I think they're all valid. I'll share one very useful piece of advice a friend of mine who is now at UPT for heavies gave me, and it proved useful for me in recently getting picked up for a fighter unit as well.
"in the Guard they're trying to make a decision of 'This guy isn't even military yet, let along a military pilot, and I'm going to select him to be my wingman and trust him with my life for the 10 years based solely on his past achievements and his demeanor'"
@Cherokeeflyer is spot on in emphasizing a focus on how you have overcome adversity and learned from mistakes. Everyone will be tested at some point in training, so if you show up talking about how great you are and how you'll sail through UPT, it doesn't make a good impression. If you can tell a compelling story about a time you failed or screwed up bad but rose to the occasion and bounced back, that'll help you stand out. You want them to see that you're humble, will be a good teammate, and won't quit when the going gets rough.
@hockeydork hit the nail on the head when he said anyone who's made it as far as the interview has already been considered capable. If you've made it to the 10 or so finalists out of 100-200, they likely already expect you have the skills to make it through UPT. What they're looking for is to see how well you'll fit with the team, that you're excited to be there but not a fanboy, and that you're going to work your ass off to be the best teammate you can be. I am an engineer with scores in the 90s across the board. Can confirm from experience that they did not care about said scores, and were far more interested in the teamwork side of my professional career than the technical.
A couple things I did for interview prep that were helpful:
Don't let your answers come off as overly rehearsed. They don't want you to recite a canned response. Take a moment to think about the question you've been asked before you speak. Take the time to prepare so you know what to expect, but don't be a robot when you answer.
Bring a team-first attitude. Once you're in the interview your academics and test scores aren't as relevant. Focus on sharing life experiences that were valuable and taught you important lessons
Do your homework. Learn about the unit, the airframe, and be able to tell them why you want to be there more than anyone else.
Be authentic. It's easy to tell the people who are trying too hard from the people who are relaxed and confident. I've seen a number of interview candidates try to talk like they're already military pilots, and it was obviously off-putting to everyone in the room.
I can't speak to the Bogidope prep since I did not make use of it. I found the standard interview questions thread in this forum to be quite helpful. Best of luck to you.