I turned developer options 'off', but is there anything else that needs to be done? Not my phone so don't want to mess anything up :-)
You can actually hide the Developer options permanently from the menu until someone enables it again. Just follow this -
Menu > Settings > Apps > All apps > (find) Settings > Clear data > Confirm
Developers options will be turned off automatically although they are enabled by following the above step.
After Developer mode is disabled, that will put your phone back into the same state that it was in before Developer mode was enabled. It will disable all developer options that could lead to security issues (Allowing ADB, etc.) and the slightly power draining options (show touch, running processes) that are open to developers.
However, as @Andrew T. points out, you won't be able to hide the developer options. The only way to re-hide them is to do a factory reset (which probably isn't worth it).
Yes, there is a way to hide it. But the options like USB debugging, if turned on, will remain turned on.
It'll only hide the developer option.
Go to Settings → Applications.
Swipe and go to All applications.There will be an app called 'Settings'
Click on it → 'Clear data'.
Now, the Settings app will automatically close. Open Settings app again and Developer options should be gone.
It worked on my Android phone (running KitKat).
Note that it will only hide the options, but the settings would remain as it were before. For resetting the options, you need to do it manually.