Strong passwords are not easy to come up with and even harder to remember. Komando.com has some suggestions.
Don’t make passwords easy to guess. People are still using passwords like 123456 or other easy passwords.
Make passwords 8 characters or more. They should be different types of characters and include upper case, lower case, numbers, and symbols.
Don’t use the same passwords everywhere. Use a unique password for every account.
Consider a password manager like LastPass, KeePass, Dashlane, or 1Password. You can even have your password manager generate a strong password for you. As long as you make your main password for the manager complex, you won’t even have to know your passwords.