Install a Small Safe
Install the wall safe or cylinder floor safe by bolting it to the floor (most safes have holes inside for just that purpose). Hide it in the corner of a closet or other inconspicuous area. Or mount the wall safe inside a wall and cover it with a picture. Or chip out a hole in your concrete slab and stick in the floor safe, then pour new concrete around it.
Keep Spare Keys in a Lock Box
Know Who's There
Avoid uncertainty by installing a wide-angle door viewer. The one shown here from M.A.G. Engineering and Manufacturing Co. (magsecurity.com, No. 8720) offers a 160-degree view and is available on the company's website. Install it just like a standard peephole—drill a hole from each side and screw it in.