Prepping for labor/VBAC

Anyone have any tips for preparing yourself for labor, specifically a VBAC? The hardest part for me last time was pushing, it's like no matter how hard I tried I couldn't push hard enough to get him out and then the doctor was frustrated so she sent me for a c section. Is there anything to make that part easier? We got so far last time, you could literally see his head but I just couldn't get him out, and I don't want to "fail" again :(