"…Any departure from his customary manner of holding, shuffling, cutting or dealing the cards may be noticed, and is consequently avoided.
In dealing, one particular position for the left hand fingers is ever adhered to, and the action of the right hand in taking off the cards and the time or rapidity of the dealing is made as uniform as possible. In cutting the rule holds good, and the true cut is made with the same movements as the "blind." Whether the procedure is true or "blind" the same apparent action is maintained throughout."
From The Expert at the Card Table by S. W. Erdnase, 1901. This book has been extremely influential in the magical community for many years.