To bake polymer clay, you should preheat your oven to the manufacturers advised temperature, which is usually between 230°F - 275°F. The baking time is typically 15 - 30 minutes for each ¼ inch thickness. Here are some general steps to follow when baking polymer clay:

1. Preheat your oven based on the package instructions. Make sure your oven can reach and maintain the correct temperature and has good ventilation.
2. Line a flat baking sheet with parchment paper or cardstock.
3. Carefully place your project onto the parchment paper.
4. Cover the clay with a tented piece of aluminum foil or cover it with an upside-down baking pan.
5. Bake your clay at the recommended temperature for at least the recommended amount of time.
6. After baking, let the clay cool completely before handling it.

Its important to note that the baking time and temperature can vary depending on the brand of polymer clay you are using. Always check the package instructions for the most accurate information. Additionally, its recommended to test the accuracy of your oven temperature with an oven thermometer before baking.