For higher security... Don't share your password(s) with others - this includes me. I know I've asked for passwords in the past to check out a complaint from a user, but I suggest that they change it to a temporary one, and then change it back when I'm done.
Choose complicated passwords, which include both alpha and numeric characters (or special characters like ! and *), and are 8 characters or longer. Dictionary words and names could be "cracked" by a password cracker program, if someone got hold of the password file through an unsecure server or other means.
Don't use the same password at every site you visit. Especially when finances are involved.
Keep a firewall on your computer. This will help prevent anyone from gathering passwords that may have been saved on your computer.
Feel free to add more tips regarding passwords!