Android 4.2 and higher - Developer Options/USB Debugging

In Android 4.2 and higher versions, the Developer Options menu and USB Debugging option have been hidden. In former 4.X versions of Android, USB Debugging option is under Developer Options menu.
Go to "Settings".
Scroll down to the bottom and tap "About phone" or "About tablet",
Scroll down to the bottom of the "About phone" and locate the "Build Number" field.
Tap the Build number field seven times to enable Developer Options. Tap a few times and you'll see a countdown that reads "You are now 3 steps away from being a developer."
When you are done, you'll see the message "You are now a developer!"