Is there a 'correct' pattern for Anglicans and/or Roman Catholics when crossing yourself?

Some Anglicans 'cross themselves' at various points of an Anglican church service. It is common practice for Roman Catholics. Is there in standard Roman Catholic or Anglican catachesis / instruction any guidance as to a 'correct' motion when crossing yourself:

• left-to-right or right-to-left, for example?
• the horizontal motion first, or the vertical?