I can tell you first hand what we are doing. My lo was breach so she had a very flat head. We went to a physiotherapist to address the issue.
We have been told to lay lo in her crib on her side. We have a rolled up towel behind her to prop her up and a pillow infant of her (not close to her face). They have had us rotating the sides every 3 weeks. Now that her head is no longer flat, we have been told to rotate the side she sleeps on every night in order to keep it even.
I really hesitated on this at first because I know that you are not supposed to put anything in the crib with a newborn but in our situation we felt it was necessary. I am not recommending anything for your lo, I just want to let you know how we were able to fix our lo's flat head.
To be honest if your lo is not already dealing with flat head I wouldn't worry much. Try to keep lo propped up and sitting in different positions and I am sure all will be fine.
