Do not use obvious combinations such as month and year or department and extension. Do not use names, telephone numbers, birthdays, children or pet names or any other information easily obtainable about you. It must be significantly different from the previous. It cannot start or end with the initials of the person. It cannot be the same as the userid.
Good passwords utilize both numbers and letters.
You are responsible for your own computer account and password. Memorize your passwords Do not write them down. Do not let anyone else use your account. Do not let anyone watch you type in your password. Lock your screen with a screen saver with password protection or log out whenever you have to leave your computer.