Last Christmas I saw a recipe for Cornstarch Clay to make ornaments. So, after I was done baking Christmas Cookies, I whipped up a batch and made a giant mess (as seen below).
The recipe is as follows:
2 cups Baking Soda
1 cup Cornstarch
1 1/4 cup Water
Stir all ingredients together in a stove pot and bring to a boil. Cook the dough until it thickens to the consistency of mashed potatoes. Then remove the dough from the heat (turn it out onto some parchment paper or onto a plate) and let it cool. I found that the dough was the easiest to work with when it was luke warm--not cold and definitely not hot. When I worked with the dough too hot, the dough was too loose and stuck to everything. When it was cold, it was crumbly.
Once the dough is the right temperature, roll it out on a cornstarched surface (I used a silicone mat) and cut out with cookie cutters.
Be sure to poke your hole at the top of the ornament (I used a chop stick). You can then let them air dry or pop them in a 250 degree oven until they are dry. I let them air dry and it took a couple of days before they were completely dry.
A few of the ornaments dried with cracks in them, so I filled the cracks with white Elmer's glue. Then I used some fine grit sand paper to remove any deformities or jagged edges. I wanted to try to paint some of the ornaments, so I spray painted them all with a white primer and let them dry.
When they were all dry from the spray painting, they were ready for whatever I wanted to do with them. Some looked great white and could be hung on the tree right away. Others I wanted to paint (like the Star Wars cut-outs), and I'm still working on getting those just right.
Some of the snowflake ornaments I thought would look cute with some glitter on them. So I coated them with Mod Podge and sprinkled some white/clear glitter and just a bit of silver glitter on them. When the glue was dry from the first round, I applied additional Mod Podge over the glitter to keep them from shedding.
Admittedly, I've been working on these ornaments off and and on since last Christmas, so it feels good to finally get some of them hanging on the tree. It ended up being more work than I thought it would be. However, if your goal is to make plain white ornaments, it's not too big of a project, and in the end, I like how my snowflakes turned out.