Getting them out of the door in time basically you just have to have a confidence about you that the time is done no bullshit you wont let them over stay.

I find these to be quite effective
-handing them a bag and wipes to clean themselves
-sitting up if they are still lying on the bed
-putting your clothes back on
-offering them there clothes.
-offering a shower
-putting an over head light on makes it bright and changes the mood.
-I always put a timer on for anything an hour or under
Hope that helps xx