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?
For Catholics, it's using the right hand, forehead-chest-left shoulder-right shoulder.


  The Sign of the Cross  (from the Fountain of Catholic Knowledge,
  OFFICE OF CATHOLIC PUBLICATIONS, Imprimatur, 1877; and from THE
  CATECHIST, by the Very Rev. Canon Howe, Imprimatur, 1898)
  
  MAKING THE SIGN OF THE CROSS  
  
  The Sign of the Cross is a sacramental if we make it with the right
  hand by touching the forehead (showing our belief in the Cross), the
  breast (showing our love of the Cross), and the shoulders (showing our
  readiness to bear the Cross). Sometimes a triple Cross is made with
  the thumb for example at the reading of the Gospel. It is made on the
  forehead, on the heart, and on the lips in order to show our readiness
  to profess the Cross.


See also the Baltimore Catechism (1064). 


  Q. 1064. How do we make the sign of the cross?
  
  A. We make the sign of the cross by putting the right hand to the
  forehead, then on the breast, and then to the left and right
  shoulders, saying, "In the name of the Father, and of the Son, and of
  the Holy Ghost, Amen."


It is worth noting that the sign of the cross (for a Catholic) is a sacramental1.  

That isn't how it was always done

The above sequence is comparatively new.  The previous tradition had lasted for over a thousand years.  


  The early Church Fathers attested to the use of the sign of the cross.
  Tertullian ((De corona, 30, ~ A.D 250) described the commonness of the
  sign of the cross:  “In all our travels and movements, in all our
  coming in and going out, in putting on our shoes, at the bath, at the
  table, in lighting our candles, in lying down, in sitting down,
  whatever employment occupies us, we mark our foreheads with the sign
  of the cross”


As described by Pope Innocent III2 it includes an explanation as to what each motion signifies.  This is how the Greek Orthodox still do it: head, breast, right shoulder, left shoulder.     

D.D. Emmons offers an explanation  


  For more than 1,200 years most Catholics made the Sign of the Cross in
  a like manner — that is, people in the Eastern and Western Church
  touched their forehead, their breast, and their shoulders, going right
  to left, with three fingers. Before he became pope, Innocent III wrote
  in The Sacred Mystery of the Altar, “The Sign of the Cross is made
  with three fingers, because it is imprinted under invocation of the
  Trinity… so that it descends from the upper part to the lower, and
  crosses over from the right hand to the left because Christ came down
  from the heaven to the Earth and crossed over from the Jews to the
  Gentiles.”  
  
  By the end of the Middle Ages, however, Western Catholics were making
  the Sign of the Cross using the hand in place of the fingers and
  touching the left shoulder first.  Among the sources documenting this
  method and the rationale is a 15th-century devotion used by the nuns
  of the Brigittine Monastery of Sion in Isleworth, England, which
  stated that one should begin with the head and move downward, then to
  the left side, and then to the right. The devotion supported this
  form, saying that Jesus came down from the Father (forehead), was born
  as man (breast), suffered on the Cross (left shoulder), and ascended
  into heaven to sit at the right hand of the Father (right shoulder). 
  This method became the standard in the Western Church. It is not clear
  why the changes took place or why they did not also take root in the
  Eastern Church, which continues using three fingers to make the Sign
  of the Cross and from right to left.


Anglicans are "a Western Church"

The Anglican confession uses the same form as the Catholics (see the origin of this practice, per Emmons).  (The source is a current website article written by an Anglican Pastor, Greg Goebel3). 


  How do I make the sign?
  
  The hand and finger traces Christ’s cross upon one’s head, heart
  (center of chest), left shoulder and right shoulder.  In the East it
  is right, then left shoulder. In some traditions, the finger is kissed
  after making the sign, or returned to the heart.  When a priest or
  bishop is blessing the people, he makes the sign as if signing them.
  This means that rather than signing himself, he moves from their left
  to their right.





  1The characteristics of sacramentals 
  
  1668 Sacramentals are instituted for the sanctification of certain
  ministries of the Church, certain states of life, a great variety of
  circumstances in Christian life, and the use of many things helpful to
  man. ... They always include a prayer, often accompanied by a specific sign, such as the laying on of hands, the sign of the cross, or the sprinkling of holy water (which recalls Baptism). 
  
  1670 Sacramentals do not confer the grace of the Holy Spirit in the
  way that the sacraments do, but by the Church's prayer, they prepare
  us to receive grace and dispose us to cooperate with it.   


2 (Innocentius III, De sacro altaris mysterio, II, xlv in Patrologia Latina 217, 825C--D.)

3  "Greg {Goebel} is the founder of Anglican Pastor and serves as editor and one of the writers. He is an Anglican Priest of the Anglican Church in North America."