Good drill for making sure my arm swing doesn't get below my shoulder tilt plane?

[T33ith1gh84]

I've been having trouble lately with my arms continuing to move deeper and behind me during my swing and causes me to come slightly over the top on the downswing. I also tend to takeaway the club on a slight inside path, but have been working at a more straight away takeaway.

 

[Jared Willerson]

Take a look at the Soft Draw pattern video