Consider using a passphrase, for example: Dogs like 2 rock and roll

• Must be at least 12 characters.
  
• Must contain at least one character from three of the following four groups. (space is considered a special character)
  • upper case letters A-Z
  • lower case letters a-z
  • numeric digits 0-9
  • special characters ~ ` ! # $ % * ( ) _ + - = { } [ ] \ : ' ; ? , . /
• Spaces are allowed.