Here's a couple of pictures of how it needs to be skewed for Astra 19.2 from Berkshire.
The skew for that satellite from this location should be 15 degrees clockwise, but as can be seen from the photo, what is actually required is around 40 degrees anti-clockwise.
The LNB does have a feint scale on the top, but many users will miss this and assume that the cable connector should be at the bottom and more or less vertical.
