Our sweet gal was more than happy to comply with this fun project.
All you need is 1/2 cup cornstarch, 1 cup baking soda, 3/4 cup water, a small saucepan, and a spoon.
Mix the cornstarch and baking soda in a saucepan. Add the water slowly, stirring as you pour. Heat the mixture over medium heat and stir constantly. After a minute or two you'll notice the mixture begin to thicken on the bottom and it's important to stir, stir, stir.
Remove from the heat and let the clay cool until you can handle it comfortably. It's surprisingly smooth and pliable! Knead it for a minute to make it really smooth.
Make the paw prints by separating a small piece of clay, rolling it in your hands to make a ball, then pressing it to flatten. Tip-toe over to your pet and quickly press their paw into the clay. Press as firmly and evenly as you can. Use a bamboo skewer or toothpick to make a small hole at the top if you'd like to turn your paw print into an ornament.
Place your paw prints on a cookie sheet lined with parchment paper or aluminum foil. Bake at 250F (121C) for 30 minutes. One of my prints was a little thicker than the others and the back wasn't totally hardened at this point, so I just flipped all of them over and baked for 20 more minutes. When they are cool you can use a Sharpie marker to write your pet's name on the back (especially if you're like me and have more than one pet!).