To sign state, hold up your non-dominant hand flat, with the palm facing the dominant side of your body. Then take your dominant hand and form it into the ASL letter S sign, and starting from the top, touch your 'S' fist to your fingertips, then move it away and down a bit and touch it to the base of your palm.
Teach your toddler the state sign when you are taking a road trip or a plane ride, and you are about to cross state borders. You can also teach the sign when you are watching a feature on TV or reading a story about the tourism highlights across different states.
This is a useful flash card taught best in conjunction with actual road trips or watching shows featuring the unique attributes of different states across America.