Treat your appointment as executor as if it were a sacred trust. Whether named in the will or appointed by the court, you owe the highest duty of good faith and fair dealing prescribed by law. Think of these responsibilities as those imposed on a psychiatrist to his patient, an attorney to her client and a mother to her child. As you perform the different duties required of an executor, from filing tax returns to investing estate assets, keep protection of the estate as your top priority.
Understand that your duties officially begin after the court approves your petition for probate and for the issuance of letters testamentary, authorizing you to administer the estate. However, your fiduciary responsibilities relate back to include any estate-related actions you took before filing the petition. Act with complete honesty from the get-go and avoid even the appearance of partiality or impropriety.
Perform every duty involving estate finances with absolute accuracy. Rely on accounting firms, if necessary, to fill out tax forms, prepare asset inventories and double-check calculations. The executor's fiduciary duties absolutely preclude any self-interest or duplicity -- for example, never sell estate assets to friends or relations. When you value or liquidate estate assets, obtain professional advice and follow it.