It’s better to choose the lightweight knitted hat; you can use it to keep babies’ body temperature, you may buy several, so as not fuss to find it when you need it.
You should make sure the cap fabric is with soft handfeel rather than rough handfeel which would make the skin itchy even achy.
It would be best to carry your baby when you want to buy the baby cap, so that the baby can try it on at any time in order to find whether good looking and suitable or not. After the baby tried it on, you should make certain that the hat is just right for the baby's head size, not too loose or too tight. If the cap is too tight, it would leave brim trace on baby’s head.
According to different season, you should choose hats with different color and style.
And what's more about the purchase of baby cap ? Could you add more tips?