Your password should contain numbers, uppercase letters, lowercase letters and symbols.
Your password should longer. Your longer password is the stronger password.
Don't serialise by using password first letters and then numbers. Mix it up.
Change passwords regularly, every month or weekly for more security.
Use different password for different places.
Example of Strong Password - 1f8R4$ff8eP443&
"1f8R4$ff8eP443&" this password is impossible to be hacked by Brute force or by Other automatic dictionary attacks. Because Brute force tries all possibilities and this password contains number, symbols, uppercase and lowercase character and it's also a lengthy password, so that can take many years to get this password. This password doesn't contains any dictionary word so it's impossible to be hacked by any dictionary password cracking software.