What should a password policy contain to reduce a hackers ability to crack the passwords?

Creating a strong password is an important part of protecting your account. T he following character sets should all be included in every password:

uppercase letters such as A, B, C; lowercase letters such as a, b, c; numerals such as 1, 2, 3; special characters such as $,?, &; alt characters such as µ, £, Æ. (Cliff)

Misspell words or create acronyms;

Use punctuation characters to separate words or acronyms;

Change passwords every 6 to 12 months;

Use variable-length passwords;

Don’t rely completely on similar-looking characters, such as 3 instead of E, 5 instead of S, or! instead of 1.