Forbes: Celebrities are not the only ones to make mistakes with their estate planning. It happens to people all across the country on a regular basis. The end result — just like with the rich and famous — often is an ugly and expensive family fight in court. One of the most common estate planning mistakes that people make is joint ownership.

For the most part, we’re not talking about when a husband and wife have joint bank accounts or the title to their home is held in both of their names. While not ideal for estate planning, this is quite common and can often be used without problems, except in many second-marriage situations or large estates that may suffer adverse tax consequences.

The area where we see significant problems, however, is when a parent adds a child’s name to an asset, such as a bank account, investment, or real estate. This is often done to help with bill paying, as a will-substitute to avoid probate court (often called a “poor-man’s will”), or simply to help an elderly loved one who needs assistance managing his or her assets. This is a big no-no!