Are there other ways to improve Apple ID security besides two-factor authentication?

Hello, I'm from Ukraine, on November 26 at around 7:00 PM I found out that my accounts were hacked: Apple ID and Google account. The accounts were hacked, although both accounts had two-factor authentication. It's good that I noticed and managed to change the password, as well as remove devices unknown to me. It was a painful experience for me, because some accounts that were tied to Apple ID and Google account were stolen. Are there any other ways to protect my accounts?