I also use low top trail running shoes. Did a lot of trial and error years back when I got into my first mammoth. Regular boots gave me nasty blisters and high tops weren’t very comfortable either. I ended up with low top trail running shoes, dr scholls inserts and darn tough wool socks. In 3 mammoths thus far, not a single blister. Will be at mammoth II in a few weeks running the same as well.