In the Peak Performance Golf Swing, the head should stay still from takeaway to impact. That means your practice swing should follow the same rules.
I had a question come in that asked about PGA TOUR players and their warmup swings. Observations were made that suggested some golfers move their head quite a bit during a practice swing. Should you be doing the same when playing golf? Hopefully you answered no!
You don't want to move your head during your practice swings or your actual swing. Stay still and maintain your angles! Let the club release to impact and swing right up to the T-finish.
Keep it vertical!