I really think staying active in labor made a big difference for me. I got an epidural at 4cm with my first so I was in bed for basically all of active labor, and I ended up with a c/s for OP/failure to descend. With my VBAC I moved around and stayed upright and basically did what felt most comfortable. I know Gus was OP the morning before I went into labor, so I did a lot of walking and some time on hands and knees that day. He was born OA so at some point he turned on his own, though I am not sure when.
Not sure if that is helpful but that is what I did. :)