That is pretty much the only thing you can do because I know in Tennessee if you dont have the posted signs up and you catch some tresspassers you can't prosecute them. So make sure they are up and are in plain sight so that they cant say they didnt see them. Or in MO I think you can just spray paint a Purple Spot on the tree closest to the property line. I believe that is accepted in place of a no tresspassing sign. Hope this helps