I don't know if anyone has posted this yet but here goes!
Homemade Baking Powder
1/4C. cream of tarter
2Tbsp. baking soda
Sift together 3 times & transfer to a clean , tight-sealing jar. Store at room temp away from sunlight for up to 6 weeks. Makes about 1/2C.
From The Gift of Southern Cooking by Edna Lewis & Scott Peacock