Along with researching on my own, my midwives also had some advice for me to better my chances of a successful VBAC.
One thing they had me take was magnesium. It has to be the Magnesium aspartate or Orotate because any other form of magnesium is not helpful. They have done their own informal "studies" that showed this type of magnesium helped women have a better and shorter labor. I was all for that after 30 hours with my first one!
As for my diet, they of course wanted me to eat healthy, but they really wanted me to go off sugar, milk, and wheat. The sugar wasn't too bad---I wish I still had the will power to be off of it entirely now. :) The milk I substituted unsweetened Almond milk, which I didn't mind at all. I prefer the Blue Diamond Brand though. For the wheat, I didn't totally eliminate, but I did cut down. Some of the reasons they asked me to make these changes were, for one, they are healthier but also to not have my baby's growth on these empty calories that could tend to grow a bigger baby. Not to say you can't give birth naturally to a big baby but to just help me in maybe having a little bit of a smaller baby this time. They also suggested eating lots of protein to keep muscle integrity as strong as possible. Also to cut carbs as much as I could, suggested goat protein powder, spiralina, lots of good veggies, and drinking kefir.
They of course wanted me to keep my body strong and ready for labor so encouraged exercises like walking, pelvic tilts, squatting and being on my hands and knees.
So I don't know if all these things really did help, but as for the shorter labor I went from 30 hours to 10 hours. I gained a lot less weight from 40 pounds to 17 pounds, and my baby was smaller from 9 lbs. 6 oz. to 8 lbs. 7 oz. Who knows if these things had any contributing factors to any of these outcomes, but I was wanting to try anything that might potentially help increase my success in having the VBAC I wanted, so I thought I would pass it along to you in case you might benefit from these changes as well.