played course again today, down to 55 , from 79 getting there

thanks for the welcome, used some of the hints ive found on net,, the most useful I came across which gripto use, I seem to have slotted into the crossover hold quite easily, and it feels really comfortable. My stance and swing are still a bit sporadic , and my playing partner tells me i have a habit of leaning back after my swing, any tips on rectifying this?