Use a Lengthy Password: the number of combinations an attacker has to try increases with an increase in password characters.
Add some complexity to the password:
Use lowercase, uppercase letters, numbers, symbols etc. This makes it harder to break.
Use unique passwords that are tough to guess. As a word of caution: Don't use date of birth, and other important events in your life as password.
Don't use similar passwords on different platforms. If you do so it may lead to Credential Stuffing.
Change your Passwords at regular intervals. You can do so on monthly, quarterly basis depending on the kind of work that you do.
If required, use a reputed Password Manager. As we use multiple platforms, it gets tough to remember passwords for all of them.
Memorize the password if you can. It's the best approach. That would do away requirement of having a password manager.
Enable Multi-factor authentication (MFA), it keeps your account safe. There are numerous authentication methods available, choose the one you believe is good for you.