The RCIA director at our parish said it was liturgically improper to bless yourself with the sign of the cross after receiving Communion. Can you point me to a Church document defining the appropriateness of this gesture?
The burden of proof lies with your RCIA director. Ask him or her to show you a Church document that states that the sign of the cross is improper after receiving the Eucharist. Such a document does not exist. The sign of the cross is always appropriate.