I'm all about following what their sleeping routine is at home and then once they are fully comfortable and settled in then I slowly get them to fit into our schedule. If they need a bottle, they get a bottle, if they sleep with a special blankie, they need to have that blankie here. I always make sure parents give me all the details in regards to how they put their child to sleep and follow it, (besides rocking them and reading them stories). But sometimes its that one little detail that they've forgotten to tell you that makes all the difference. With my newest one, the mom told me that they go around the house and say "good night" to everything on their way to the room ....like goodnight room, good night kitchen, good night teddy, good night doggie, etc....and that he sleeps in a sleep sack. I had trouble with him even with following that, and he wasn't sleeping very long. Turns out, he had to be out of his pants before he was put into the sack, which helped for a few days, but then I thought I heard him say blankie....turns out out he also needed a specific blankie and cow which the mom thought he wasn't attached to as he never showed any signs that he needed them ever. After that, he started sleeping immediately.
Also, i never ever stay in the room with the kids when they go down for the nap. I just explain that it is sleepy time and leave matter of factly never turning back. If you do it from the start, they know and understand that that is what happens. My philosophy is that If they have everything that they are used to and they are truly tired and ready to sleep, that their body will naturally just allow them to with ease. But that's the big difference with me. Instead of trying to make them fit my schedule from the start, i just always go with theirs. I find it to be easier on them and me as well. Makes for always having someone up, but eventually it merges into what the majority of the kids nap times are.