We try every day, or every other day, to scent work Ruby. It is so good to see (and hear her) sniffing the air to find what we have hidden.
We use an old, solid plastic vitamin bottle with one small hole drilled into its lid. When not in use, the hole is covered over with tape.
Inside said container are small bits of dried fish (which for Ruby, rocks her boat). She stays with one of us in a room, whilst the other hides the container, tape removed. A small piece of the fish is temporarily held in our hand to scent it before being put in the container, for the initial hide.
We use a different room each hide, on the floor, behind things, inside things, under things. She then sniffs our fishy hand, is told to go find and off she goes. When she finds it, she sits in front of it, tail wagging furiously. She is praised then rewarded with a piece of the fish.
We do this between 3 and 5 times until the container is empty and the session ends. The bottle is refilled, tape put back into place and put away until the next session.
Our trainer taught us to do this for when the weather is really horrible, it is a good way to work and mentally tire her.