Flat Headed Baby
Babies heads are really soft when they're first born so that they can squeeze through the birth canal. Because of this they heads are susceptible to getting flattened out if they're repeatedly laid the same way. The best way to avoid this is to give the baby lots of tummy time while they're awake. Also, avoid too much time in a cradle, car seat, or swing. These devices limit a newborn's ability to turn their head from side to side and build their neck muscles. It also forces their head to stay in one position for a long time. Flat cribs and bassinets are best because the baby will usually turn their head to one side instead of being flat on the back. Just make sure to turn the baby's head a different direction every once an a while if they're not turning it on their own. Otherwise they'll get flat on one side of the head!
Avery had torticollis, which is basically just REALLY tight neck muscles on one side that makes it hard for them to turn their head. She couldn't really turn her head to the left so she ended up getting a flat spot on one corner of her head. We had to do physical therapy and tons of stretches at home when she was 2-4 months old. I was told that her head shape would solidify between 4-6months old so if we weren't seeing progress she would have to wear a helmet for 6 months. Luckily we did as we were told and now her head is nice and round. No helmet needed :)