I have the old programs we had to buy for the computer, and each box has a registration number on the end. I use them in the order they are on the shelf and use 7 or 8 digits of the registration numbers.
One simple but effective technique is think of a favourite song or movie, book etc... Use an anagram of title .. eh gone with the wind becomes gwtw ... Add some numbers that are meaningful .... The longer the password the harder to crack
There is another way of course .. set your password to be "incorrect" ... Then when you need to enter it just type in gibberish... The system will then tell you what your password is :)