Checkout the swing positions of Rory and DJ. When you're practicing, try and get your setup to copy the images below.
Good spine angle - athletic posture and body position
Hands hang below chin, creating space to swing
good knee flex and feet width
shoulders align to hips and feet
Notice the excellent posture that is maintained throughout the swing - Giving hundreds of lessons each year, the number 1 issue I encounter is loss of posture on the backswing (Straightening up to help lift the club), early extension on the downswing and loss of posture through the swing causing slicing. Also notice the great weight shift and releasing the back foot - don't hold down your back foot or fall backwards through the swing.