More than 20 years ago, before The Wood Whisperer and before I had much experience in the shop, I built a country bookcase for my mother-in-law. It was probably the third piece of furniture I ever made. After several moves and more than two decades of use, it finally came back to my shop for a few repairs. That gave me a rare chance to look closely at my own beginner woodworking. Some things held up much better than I expected. Other choices, including poor back-panel construction,...