I use to explain my strategy to friends and over time I've changed from words to short phrases.
What I do is to have passwords divided in two parts: one constant, one variable
The constant part is a phrase I can easily remember and the variable part is a reference to the usage of the password, so for example:
- ILikeDarkChocolateGmail
- ILikeDarkChocolateApple
- ILikeDarkChocolateWhatever
and so on.