"Use your head!" A favorite expression from the 1940s. But if you're into antiques, "Use your nose!"
How can you tell a real antique bureau from a fake? Use your nose! Sniff inside the drawers. If you're smelling fresh wood, you'll know you've sniffed out a fake. And if you're smelling mildew, don't buy it!
How can you tell an ancient Roman lamp from a fake? Use your nose! If you're smelling fresh clay, you'll know you've found a genuine fake!