At the risk of sounding like a broken record, if you use static IPS and turn off DHCP, you have now eliminated 98% of the folks who shouldn't be on your network. It also helps to run a non-default private network.
For those of us who travel with network analysis tools on our devices, this only makes us smile, because it is the first indication that there is intelligent life running the network. Not that I would then kick-off a network scan & probe, or anything like that - oh no.
For that 98%, wireless or even physical access is now useless to them; but then it is always that 2%.
