The shelties just get locked in the basement. My room is down here as are most of their dog beds and a crate without a door on it. When I leave I put some treats in their treat balls, turn on my radio and babygate the stairs so they can't get upstairs. Works for us.

Oh btw, they are completely trustworthy in the house. The reason they are put in the basement is because they (mostly Emily) will bark at people on the street when we are gone.