The tips below are copied from wikiHow at the bottom of the page.
Don't use obvious base-words like a name, birthday or date, these are easier to crack than whole phrases.
You can also use accented letters. It makes your password much harder.
For even more security, try to use "nonsense words." Combine these with numbers to make memorable, secure
passwords. For example, "brickbeak9468."
Don't use your name, it will be easy to crack!
Mixing in numbers and letters (E.G.: j78hu5948h0gy67g) can almost be impossible to crack, so try using that
tip. If you're afraid you'll forget your password, write it down in a secure place where you won't forget it.
Take a word (for example, money), spell it backwards (yenom) and put your birthdate in between. Say you were
born February 5, 1974. So it would be yfebe5n19o74m. Hard to remember, yes, but also nearly impossibly to
crack.
Change your passwords periodically or whenever it may have become compromised. Frequent password changing is
required by company policy or federal law in some businesses, but may encourage users to choose weaker
passwords or write down their password near their computers. Don't re-use an expired password.
If you have trouble remembering all the passwords you need, try using a password manager, they can store all
your passwords securely using a single master password.