T-shirt: Select a soft, breathable t-shirt that is pleasant to sleep in. Look for choices made of cotton, modal, or other light fabrics. T-shirts with short sleeves or three-quarter sleeves are commonly used as sleepwear. Pajama Depending on your preferences and the weather, you can choose full-length pants, capri-style pants or shorts for the pyjama bottoms. Look for pyjama bottoms composed of soft materials that allow for movement while sleeping.