I started applying after SLE already happened, but my interview practice (at a state college, I did a mock interview 1x a week for 8 months specifically for this interview and the congressional nomination interviews) taught me a lot.
Blunt and honest answers
always beat the answer you think people will want to hear. In my house rep's interview, I told the board that I was a bum in high school and that as far as my high school extracurriculars went, showing up was all I really did, if even that. I was always at least 15 minutes late to band.
I then told them that the transcript describing high school me and the version of me in that room wouldn't even recognize each other and explained how my life changed later on a 2-year missionary service in Spain. I know this is not the congressional nomination interview, but I noticed very few differences between the two in my experience. I just didn't try to pretend to be what they typically see in high school aged students (I'm 21).
You also absolutely need to tell a time when you've failed hard and learned from it. Try your best to use the STAR method when answering interview questions, and end the R (result) of the STAR method explaining what you've become from that experience. Memorizing statements isn't going to help you at all, but have a good idea of what points you'll explain to help the interviewer see who you are and help connect your qualities with stuff that is compatible with core values of the Army.
At first I felt like I had very few stories in my life to share, but after reps and reps of this, I started to learn just how many good examples of learning from failure I had and began to get more out of my everyday life. It's not only helped me be an example of change but also understand other people in ROTC and help them do more. Really excited for y'all; hope the interview goes well. I've heard that the SLE interview is more of a chill one-on-one conversation than a formal interview with a field force rep.
This video might help:
Hope this helps, but maybe my fellow incoming plebes that did SLE can chime in too. Good luck!
Also, don't feel like you have to respond immediately to questions! I took plenty of time to think about the question and not spit out an undercooked answer, like upwards of 10 seconds!