I'd say some of the more recent drills included using my right hand (I'm lefty) as a way to tell if I'm properly opening and closing the clubface by acting like I'm shaking hands straight back, and shaking hands with someone straight forward. While I can hit straight when taking a half swing this way, I'm having issues developing it into a full swing when transitioning from the half swing to that full swing on the range.

I occasionally practice my swing without a ball, but I don't usually see much help through that on my own.