Other than adding toggle system settings buttons to your Home Screen, you can add settings shortcuts on Xperia Z Home Screen and get direct access to their menu. To do so, do as follows:
1. Press and hold your finger on an empty place on the Home Screen
2. On the opened menu, tap Apps.
3. Tap Shortcuts
4. Scroll to right and tap Settings Shortcuts
5. Now, you have the option to add the shortcut of these settings to the Home Screen of your device: Accessibility, Apps, Battery, Bluetooth, Data Usage, Display, Location services, Power management, Sound, Tethering & portable hotspot, VPN, Wi-Fi