Self-rising flour is measured the same way all-purpose flour is measured. Use a spoon to fluff the flour a little bit. This helps to aerate the flour and prevent it from becoming compacted during storage. Gently spoon the flour into a dry measuring cup and use a straight edge, like the back of a knife or a spatula, to level off the excess flour. Run the straight edge across the top of the measuring cup to remove any extra flour, leaving a level measurement.