If you want to create random passphrases based on certain wordlists, a tool that generates these passphrases should be used rather than generating them yourself. Here comes an introduction to four different methods of creating such random passphrases.
This is a mathematical post which is related to the xkcd 936 comic about password strength. The central question is: What is better for passwords? A password containing a few random characters or a passphrase containing a (less) few random words? Here comes a mathematical discussion.
This is a short post in which I show the options I am using when generating random passwords with the Password Generator that ships with the password safe KeePass. The character set should be as big as possible while not containing letters that could confuse the end-user. Of course, all upper- & lower-case alphabetic characters as well as the digits are included. For all other symbols, I chose those which are inside the ASCII table as well as writeable with the keyboard layouts for US and German keyboards.