I have much curlier white-girl hair than Ester’s picture, and I just switched to a silk/satin pillowcase and I am surprised to say it helps with day 2 frizz! It’s not a complete solution, but it made a noticeable difference to me. The one I got was ~$7 at Bed Bath and Beyond, labeled “pillow protector” or something like that, and apparently it’s aloe-infused, whatever that means for fabric. One of my other curly-haired friends also swears by t-shirt towels and satin pillowcases, and her hair looks great.