I highly recommend a protein treatment for enhancing and defining curls. My hair is naturally wavy, yet pretty frizzy. Protein treatments have done wonders for my hair by strengthening it, limiting breakage, and making my curls way more defined than I could ever imagine. Well, after my very first application, my waves actually became well-structured curls and maintained that form for days. I started with a homemade rice water rinse, and yes, there are salon versions like keratin or bond-building treatments for super strengthening. It's all about balance; regular moisturizing post-protein treatment is important to keep your hair from drying out. The difference is actually pretty noticeable after a single session.
A high-quality anti-frizz oil. This forms a protective barrier around each curl, locking in moisture and preventing unwanted frizz, no matter if it's humid or dry outside.