I used to use Bisquick, but I've since discovered that I like scratch biscuits better. Here's the very best biscuit recipe I've found, from La Belle Cuisine. The author notes that lard, which is rendered animal fat, makes a crisper biscuit than vegetable shortening. I don't keep lard around and these are pretty crisp with Crisco; one day I'll try them with lard.
If you do not keep buttermilk or buttermilk solids around you can use 1 tablespoon of vinegar or lemon juice in enough milk to make one cup total (remember the acid will flavor the milk, so white vinegar is best). Let it stand five minutes so the milk sours properly.
2 cups all-purpose flour, plus more as needed
1/4 teaspoon baking soda
1 tablespoon baking powder
1 teaspoon salt
6 tablespoons lard or solid vegetable shortening
3/4 cup buttermilk
Makes 25 to 30 biscuits
pastry blender or fork until the mixture has the texture of coarse corn meal. Add the buttermilk and mix with your hand, lightly but thoroughly. Add a little more flour if the dough is too sticky. Knead for 1 minute. Wrap in wax paper or foil and refrigerate until well chilled, at least 20 minutes.
Preheat the oven to 450 degrees F. Roll the dough out 1/2 inch thick on a lightly floured surface or pastry cloth. (Always roll from the center out for tender, crisp biscuits.) Cut the dough into the desired size biscuits.
Place the biscuits on a dark baking sheet and bake until golden brown, 10 to 12 minutes.
I used a 3-inch biscuit cutter and got 12 biscuits. I don't have a dark baking sheet; the difference is whether the pan absorbs or reflects heat, but mine came out fine. Serve them warm with butter or jam; smother them in country gravy for breakfast; or use them instead of bread in your sandwich!