White Lily or Martha White self rising flour makes great biscuits. To make them even fluffier add a teaspoon of baking soda to react with the acidity of the buttermilk.
I use Martha White. I can’t make good homemade biscuits like my Mammaw did however. I’ve tried. Mammaw would make and roll them with one hand. Always amazed me. Only found one restaurant (in Memphis) that made them like hers. Hardees is close, but not quite as good. I DO make GREAT cornbread! It’s all in having a properly seasoned cast iron pan
I’m told if you switch the milk with sprite or seven-up, your biscuits will be very high and very fluffy. Never tried it; just sounds too weird to me. I suppose you could also use carbonated water and powdered milk. THAT, I might try.