Do your muffins always turn out dense? You might not be scooping the flour properly which results in too much flour for the recipe. The correct method is to use a small spoon to scoop the flour into your measuring cup. Never scoop directly from the bag with your measuring cup! Also, don't tap the measuring cup on the counter as you're adding the flour. Simply spoon it in until overflowing then use a straight edge to level off the excess back into the bag.