How you knead depends on your strength and body structure, but whether you do it with one hand or two—or your feet, for that matter!—what you do to the dough is generally the same. Plop the dough onto a floured working surface, preferably one that allows for a full extension of your arms, then flatten it (it will be an uneven mass at first). Fold the dough not quite in half toward you, then, with the heels of your floured hands, press into the dough and away from you. If it is a heavy dough, you may have to push it several times to stretch it somewhat. Give it a quarter turn, fold the dough toward you again, and repeat the pushing, turning, and folding, flouring the board and your hands as needed. In about 5 to 10 minutes the dough will become springy and elastic, no longer a resistant, sullen lump. The gluten being developed by your dedicated kneading will be forming a fine, elastic interior mesh to enclose the tiny air bubbles that will be produced by the action of the yeast. When the dough has been sufficiently kneaded, the surface will be smooth and often marked with tiny blisters.