PREHEAT YOUR OVEN TO 425°F.
MIX TOGETHER THE DRY INGREDIENTS. WITH TWO KNIVES, A PASTRY BLENDER, OR YOUR FINGERTIPS, CUT OR RUB THE BUTTER OR SHORTENING IN UNTIL THE MIXTURE LOOKS LIKE BREAD CRUMBS.
ADD THE LIQUID ALL AT ONCE, MIXING QUICKLY AND GENTLY FOR ABOUT 20 SECONDS UNTIL YOU HAVE A SOFT DOUGH.
TO MAKE DROP BISCUITS: DROP THE DOUGH BY THE SPOONFUL ONTO A LIGHTLY FLOURED BAKING SHEET; OR FOR TIDIER SHAPES, FILL THE CUPS OF A GREASED MUFFIN TIN ABOUT TWO-THIRDS FULL.
TO MAKE CUT BISCUITS: PAT THE DOUGH INTO A RECTANGLE ABOUT 3/4″ THICK. FOLD IT INTO THIRDS LIKE A LETTER AND ROLL GENTLY WITH A FLOURED ROLLING PIN UNTIL THE DOUGH IS 3/4″ THICK AGAIN.
CUT INTO CIRCLES WITH A BISCUIT CUTTER FOR TRADITIONAL ROUND BISCUITS. OR, TO AVOID LEFTOVER DOUGH SCRAPS, CUT THE DOUGH INTO SQUARES OR DIAMONDS WITH A BENCH KNIFE OR BOWL SCRAPER.
BAKE THE BISCUITS FOR 15 TO 20 MINUTES, UNTIL THEY’RE LIGHTLY BROWNED. REMOVE THEM FROM THE OVEN, AND SERVE WARM.