something my mom used to train my form was using very light weights that i could do for 35-40 reps and my first year of training i would do three sets of 4 exercises with that reps range slowly and after a while i would do it with my eyes closed while she watched to see if my muscles could remember the movements. thanks to that type of patient training i can lift 1 rep maxs now or even 115% of my one rep max and no matter how much effort i put into it my form never breaks because it's so engrained. neway just a thought if your really interested in getting your form to stick