A fiduciary is someone you've placed in a position of trust to act on your behalf. In estate planning, the fiduciaries are the executor (or personal representative) of your will, the trustee of your trust, the attorney-in-fact for your power of attorney, and your health care agent for your health care proxy.
Most of the time, my clients want to name one or more of their children as their fiduciary. They come in thinking that “Joe” should be a fiduciary because he is the oldest or the child holding the “most important” job or some other reason. I tell the client two important things. First, being a fiduciary is usually a thankless job — and it can be a JOB. There is no honor or glory in running from one bank to another to close out accounts or paying the bills or getting a house cleaned out and sold. It takes time, energy and organizational skills. The client needs to be sure that the proposed fiduciary is cut out for the job.
The second thing I tell — or ask — the client is how well does Joe handle his own money? Does he have a drinking problem? Can he hold down a job? A good fiduciary needs to have good character. If Joe is not responsible in his own life, the client shouldn't assume that Joe will somehow be more careful with the client's affairs.