Lock your computer, use strong PINs, and encrypt your hard drive.
Physical access to a device can bypass many software security controls. An attacker with physical access to an unlocked computer has access to every file, every saved password, every open session — without needing your password at all. The screen lock is the most basic physical security control.
A privacy screen is a filter placed over a laptop display that restricts the viewing angle, making your screen visible only to you and invisible to anyone sitting to your side. In airports, cafes, trains, and open-plan offices, your screen content is visible to anyone nearby. Sensitive work on a laptop in public is a real exposure.
Enable full-disk encryption on every device that holds sensitive data. On Windows, BitLocker is built in. On macOS, FileVault is built in. On modern iPhones and Android phones, encryption is enabled by default when you set a PIN. These settings make theft a hardware loss rather than a data breach.
Enable remote wipe on your mobile devices before you lose them, not after. On iOS, "Find My" includes remote wipe. On Android, "Find My Device" provides the same. Set this up now so you can act quickly if a device goes missing.