Best Practise to prepare for Theft/Loss

I have just had the first reported theft of an iPad managed through SMC 3.6, and realise that the policies i put in place may not be of much use, so I am looking for advice on how to better secure my devices.

I have initiated a remote lock and location check if/when the device next connects to the Internet, but think it is possible the new "owner" could bypass this by simply guessing the passcode and wiping the device and/or resetting through iTunes

Apart from enforcing a stronger passcode (I didnt realise what "Allow Simple Values" meant, so suspect that many of my devices will have been set up as 0000 or similar) what else could/should I do?

I didnt enable Find My Ipad feature on these iPadsas I thought i could do the same thing through SMC, but have now realised that without having FindMyIpad enabled I cant set teh Activation Lock the device based on Apple Id either, so once the iPad has been wiped (wether by myself remotely or by the thief) there is nothing to stop them registering as a new device with new Apple ID

Any recommendations on best parctise for security and or any way of turning "FindMyIpad" on retrospectively would be much appreciated!

Thanks, Dave