I searched Amazon and ebay for chemo caps, and pre-tied scarves. These are my favorites, super comfortable and cute. I bought them in a few different colors to match my clothes:

https://www.amazon.com/dp/B07CYWH1SW?ref=ppx_pop_mob_ap_share

https://www.amazon.com/dp/B077KX6MYP?ref=ppx_pop_mob_ap_share

https://www.amazon.com/dp/B07KY57RRF?ref=ppx_pop_mob_ap_share