Why do you make the sign of the cross backwards? And why so often?
In order to understand why Orthodox Christians make the sign ‘backwards,’ imagine holding a pencil. Now draw the Cross. Naturally, this action is done top-to-bottom, left-to-right. If then we turn this natural action of drawing a cross upon ourselves, it appears to go right-to-left, but the action is identical to that of drawing a cross on a piece of paper.
This image is also useful for understanding why Orthodox Christians cross themselves so often. By “drawing” the Cross upon themselves, the Orthodox Christian is marking themselves as belonging to Christ and His Kingdom. Thus, it is a means of prayer and a way that Orthodox Christians involve their body and their sense of touch in their worship of God.