I have discovered that teaching ASL handshapes first is a very effective and accurate way for non-signers, teachers and students, to learn American Sign Language for the first time. It is important that teachers understand and produce the sign correctly as they will be the ones teaching their students the signs. It is not as crucial for the students because they will gradually self-correct just as in the process of learning to speak.
By learning a specific handshape properly, teachers are able to sign many different words by just changing the location of the sign on the body, the direction of the palm of the hand and the movement of the sign, allowing the learner to not only learn one sign but a multitude of signs in a very short time. It shortens the time necessary to accomplish the goal and it enhances the teaching/learning experience.