Many Christians make use of the sign of the Cross in both public and private devotions.  They “cross” or “bless” themselves, in common parlance.  This action is done by touching with the tips of the fingers of the right hand the forehead, chest center, and left and right shoulders to form a cross.  It is not to be done with a flourish or ostentatiously, but with reverence. 

This act is indeed primarily an act of reverence.  It has several meanings or purposes, perhaps varying somewhat with the particular moment at which it is used.  It is an outward and public confession that one is a Christian.  It signifies one’s commitment to the faith.  It invokes God’s blessing on the worshipper.  Again, it may have a very incidental use as a way of keeping one’s mind on the service as it progresses!

Individual practices vary and there is no absolute rule or standard.  In general, the sign of the Cross is made at the final words of the Apostles’ or Nicene Creeds, at the final words or the Gloria in excelsis, at the word, “pardon,” in the declaration of absolution by the priest, whenever the Trinity is invoked, when kneeling down to pray upon entering a church (because the worshipper usually opens his private devotions with the words, “In the name of the Father, and the Son and the Holy Ghost”), at the invocation of the Trinity at the benediction, when concluding one’s private prayers at the end of the service, at Grace before meals, and at various other times as customary or desired.

Making the sign of the Cross is in no way commanded or required by the Anglican Church.  It is strictly an act of personal devotion, done solely by choice of the individual.  It is an ancient sign, in use from earliest times.  Its use is not the possession of any particular Christian body.  Many Christians find it personally helpful and see it as a proud, if quiet, acknowledgement of their faith.