If you’re having trouble coming up with that one strong password, consider using the Diceware method to generate a strong master password.
Diceware is used to generate cryptographically strong passphrases. Don’t let that frighten you away though, a passphrase is just a password made of words you can remember. It is based on the principle that truly random selection of words from a word-list, can result in easily memorable passwords that are also extremely resistant to attack. Traditional Diceware uses rolls of physical dice, this application uses a strong random number generator in place of the dice. Passwords that are six words or longer are thought to be safe for any very high security applications.
Try out Diceware