Your password should be something you can remember easily.
A secure password should have:
At least 8 characters.
At least 1 upper-case letter.
At least 1 lower-case letter.
At least 1 numeric.
(Punctuation symbols are strongly recommended)
Please don’t re-use passwords for multiple unrelated internet services, as a breach in the security of one (e.g.: Apple iCloud) would then render others (e.g.: your Bordernet account) open to abuse.