Signing: To do the open sign take both hands together with palms facing you. Move the two hands apart while rotating so that you end with the palms facing outwards. The sign looks like you are opening some windows.
Usage: Make the open sign when you are opening a window, and gradually expand the use to other open events, like opening a jar.
Flash Card: Click the link to view the Open Baby Sign Language Flash Card. The flash cards are printable and available in both U.S. Letter and A4 sizes.