Hi paterick,
You are quite correct in what you have read. This actual tilting of the spine angle is a position that is normally achieved naturally and more so with the longer clubs. This is primarily because the ball is positioned furher forward in your stance with the longer clubs.
I have included the photo below to give you an understanding of the slight tilt angle in the spine. Whilst this is not something that generally needs to be worked on, some people do slip into the habbit of standing to straight spined with the longer clubs - but this is generally caused by the ball being to far back in the stance.
Hope this helps
