Here is the recipe I used for baking soda clay:
1 cup baking soda
1/2 cup cornstarch
2/3 cup water
Keep stirring over medium heat until it starts to clump together. Remove from the heat and keep stirring. Use a rolling pin to roll the mixture out to about 3/4'' and start to create! Be careful, it is hot! I used a glass to cut circles and it worked really well. Also think about painting them with acrylic paint after they dry. I put them on wax paper and waited until they dried before decorating. I was too chicken to try to bake them because I thought it would stick to the pan. All that hard work! Don't forget...keep any not in use covered by a wet towel so that it doesn't dry out.
I will try to post pictures after the holidays! I have a few going out as gifts.