Choose one or more from each of the following:
- Uppercase letters
- Lowercase letters
- Numbers
- Special Characters ! " £ $ % ^ & ( ) _ + etc etc
Don't choose:
- blank passwords. You'd be surprised how many people do this.
- Substituting vowels with numbers: p4ssw0rd. This is in most password crackers
- 1337 speak - password crackers have this as well
- Passwords less than 7 characters long.
- Birthdays, names or initials of loved ones.