Start with fully dry curls before bed
Use a silk or satin pillowcase
Pineapple your hair with a loose scrunchie
Put hair in a loose top bun if curls are short
Twist or braid sections loosely for protection
Use a silk or satin bonnet
Refresh curls lightly with water or curl mist in the morning
Avoid sleeping with tight elastics
Keep hair moisturized but not overly wet
Sleep on your back or side to reduce friction