Well, I had one of those wedgie things that kept them on their sides. I had a fear of them urping while on their backs and aspirating vomit. Not good. I made sure to switch which side they slept on so their heads wouldn't get deformed. I have seen so many babies with lopsided heads or heads that are extremely flat on the back from not changing the sleeping position. I also always swaddled until they didn't like that anymore. Then it was just a blanket over the lower half of them.