Enact 2FA and Use a Security Key

You’ve probably heard it before but we’ll say it again: two-factor authentication is a really good idea. In essence, 2FA is just a way to ensure that the person logging into your online accounts is you. Many online accounts will give you the option to enact 2FA (check out Twitter’s how-to, for example). Generally speaking, you will be asked to provide another piece of identifying personal information—like a texted code to your phone or a biometric identifier—to ensure you are who you say you are.
However, I would argue the best way to set up 2FA is by investing in a security key. Security keys are small, portable pieces of hardware that can be synced with your online accounts, ensuring that the only way to get into those accounts is to be in possession of the physical key. After syncing, logins will prompt you to insert your key into whatever computer or device you’re using. If you don’t have the key, you can’t get in. Luckily, most devices are small and portable and can be hung around your keychain, ensuring that it’s never far from you and it’s difficult to lose. (Slap an Airtag on the keychain if you really want to be careful.)
There are a number of different brands to choose from, and keys generally waver around the same price range ($30 to $60): Yubico, Thetis, SoloKeys, Google Titan, and more. You can check out a full run-down here.