19. You overwork lower-fat dough.

Result: Cookies, scones, piecrusts, and biscuits turn out tough.

Recipes with lots of butter are more likely to stay moist and tender because of the fat, even if the dough is overkneaded. But without all that fat, you absolutely must use a light hand. That’s why many of our biscuit and scone recipes instruct the cook to knead the dough gently or pat it out (instead of rolling), and our cookie or piecrust recipes say to mix just until flour is incorporated.

“Whenever I make any of our cookies, I stop the mixer before the flour is completely incorporated,” says the Test Kitchen’s Deb Wise. “I do that last bit of mixing by hand, and it makes a difference.”

• Learn all about baking bread