With your infant, fill a plastic container with water and some toys outside on a warm day. Let your baby feel the water and play with the toys as you talk to them, "Your fingers are wet!" "Your toes are wet". This is a fun way to help your baby learn new words. See if she can point to a body part you name. You can say, “Where’s your tummy?” If she’s not sure after a few seconds, you can point to her tummy or guide her to point.
With toddlers, try asking what you should wash next. If they need extra help, give two choices: “What’s next? Your tummy or your arms?” For an extra challenge: Once they've mastered all the basic body parts (head, tummy, legs, back, etc.), start on some of the more advanced ones like forehead, elbow, wrist, ankles, etc.!