Since I never can remember the recipes/formulas for making your own self rising flour and cake flour, I’m posting them here where I can quickly find them.
As I continue to work to simplify my cooking and my life I’m limiting the staples I stock in my kitchen. So, I don’t keep cake flour or self rising flour in the house. My pantry is small, I use them only occasionally and they are so easy to make (when you can remember the formulas 
)
Self-Rising Flour
1 cup all-purpose flour
1 1/4 teaspoon baking powder
1/8 teaspoon salt
Whisk together the all purpose flour, baking powder and salt until well blended and use in place of 1 cup self-rising flour.
You can also make this a little healthier by using whole wheat pastry flour or white wheat flour for up to half of the all-purpose. I often use a combination of 1/3 cup whole wheat and 2/3 cup all-purpose.
Cake Flour
1 cup all-purpose flour minus 2 tablespoons
2 tablespoons cornstarch
Whisk together the all purpose flour and corn starch until well blended and use in place of 1 cup of cake flour.
Source: simple-nourished-living.com