To swaddle a newborn, lay a blanket on a flat surface in a diamond shape. Place the baby with their head above the fold. Take one corner of the blanket and wrap it snugly across the baby's chest, tucking it securely underneath their back. Finally, cover the remaining corner across the baby's chest and tuck it in, creating a secure and soothing swaddle for your newborn. Remember to ensure the swaddle is snug but not too tight for their comfort.