How to make a password that is hard to guess
Length matters more than clever spelling. A long password with mixed character types is harder to guess than a short one with symbols swapped in for letters.
Use at least 16 characters. Mix lower case letters, upper case letters, numbers, and symbols. Do not use a word from a dictionary, a name, or a date, even with a number at the end. Those are the first things a guesser tries.
Never reuse a password across sites. If one site leaks it, every site that shares it is open. A password manager fixes this: it remembers a different long password for each site, so you only need to remember one master password.
Make the password in your browser with the Password Generator, copy it, and store it in a password manager straight away. Do not email it to yourself, and do not save it in a plain text file.