How-to's are designed to teach people how to accomplish a certain task or goal. They're helpful, but almost as helpful are instructions on how not to do things, whether you're trying to make a martini or a potato gun. Let's be honest, when it comes to doing things correctly, pitfalls about. It's good to be able to see where other people have gone wrong trying to do thing you're trying to do. Some people are positive examples and others are negative examples, and it's usually pretty easy to tell the difference.