So, I posted on this a while ago, but for lack of trying to find that link I'm reposting my form check from today. This is my fifth set and I'm consciously working to keep my knees and feet together, my lower back arched, straight and upright, my chest following the weight and my elbows locked. I also am trying to ensure that I 'feel' the exercise in my obliques. I can easily say that I had at least another set of 30 in me after this one, if not two more. Let me know if there are any other pointers I could apply to improve upon this because for all intents and purposes I feel like it's mastered.
Cheers.