Brick + Beam Detroit

I take half-inch sheets of OSB plywood and cut them so they snugly fit into the opening of a door or window. I fasten these pieces of OSB into place with a hex-head deck screw. I put them in about every 18 inches along the perimeter of the piece of OSB. You can also use washer with these screws to make it even more secure, but that's a bit of overkill. This has worked quite well for me over the years. It takes about half a day to a full day to measure, cut, and place enough pieces of OSB to cover the doors and windows of a house.

Assuming that you have 120V power hooked up at your project, I suggest installing LED dusk to dawn flood lights mounted on both sides and in the back is a good deterrent to nocturnal visits by thieves. Menards has such units for abut $45 each and they last for ever. It also is helpful to get acquainted with the neighbors and give them your phone number in the event of suspicious activity is noticed. Steel door and window covers can't hurt especially if your project is in a depopulated area by itself.

Thanks for the replies.

Do you do this work for others Jon?