Butter that is too warm won't aerate properly when beaten with sugar, leading to a decidedly un-fluffy result.

Always bake in the center of the oven. A pan placed too close to the bottom of the oven will receive more heat radiating from the oven floor, baking it faster from the bottom. The reverse is true of something baked on the top rack. Always bake in the center for the most even baking and browning all around.

Only bake one type of thing at a time. Even when it seems like you're killing two birds with one stone, baking multiple recipes at the same time in one oven presents a tricky balancing act.

Claire Saffitz Quotes