From time to time we relate stories about do-it-yourself estate planning gone awry. It’s not that we get pleasure from explaining common mistakes. And we’re not just trying to terrify people about self-help. We’re trying to make it clear that the problems created by trying to save a couple dollars in legal fees so often end up costing far more than the legal advice would have cost. And the kinds of problems are hard to predict. Things that might seem reasonable to a non-lawyer can end up violating arcane — or even well-known — legal principles.