1. Set up a Bola machine (at a reasonable speed) to re-create that delivery and practice driving or defending the ball.
2. What I have noticed is that if I plant my foot too early, I never get the line right. Watch the release of the ball to gauge the line before moving your front foot. If the line is leg or middle leg, your toe should point straight down to the wickets (ump side) and your stride should be small. This becomes a lot easier if you habitually move your head first and get it close to the ball. Kevin P has a great line in one of his youtube videos: "kiss the ball".
Good luck. 
Am booking a net for some point this week, bowling machine included.
I plant my front foot in an effort to get myself coming forward because I normally sit on the back foot, I'll definitely try waiting until I pick the ball up from now on before I start moving and I will try to shorten my stride length too as it comes towards middle-leg line.
Thanks for the advice, I'll go watch the YouTube videos too!