I have all 5 children sleeping in 2 rooms. I find blackout curtains and routines to be my two secrets. We go from busy, hectic mornings to a nice lunch where I read a story to them once they all sit down to eat and then to circle time for 1/2 an hour where they are all (hopefully) sitting and winding down. Then I let them play for a few minutes while I set up the beds and within 15 minutes to 1/2 an hour they are all 5 asleep. They know how our days transition from the minute they arrive to the minute they go home and routine is very healthy for children. We have different activities and field trips every morning, but from lunch time to naptime I keep it consistent and really believe that's the secret. Busy to winding down to quiet to sleep.