I didn't think my hair was damaged. It was soft, I never used heat styling of any kind, I generally used "good" products on it, any perms I had used had long grown out, and it never frizzed, ever.
So, when I started CG, I concentrated on "no sulfate, no silicones", I didn't really worry about protein treatments (though I did choose products with protein added when possible), didn't worry about deep treatments, and just continued my "wash and go" lifestyle.
My top and front and canopy continued to just barely wave, while my back curled like crazy. I was frustrated because even though the top was not curling, it often sprouted several lovely curls, but not always or all over. I asked a few times here what I could do to get the best possible curl out of my hair, and was basically told to accept that my front was wavy, not curly.
Well, I came to understand that the desert heat, sun, and dryness may have caused damage to my hair that I hadn't noticed, so I started conditioning more and using deep conditioning treatments. Then, I used a protein treatment, and WOW! My front went overnight from slight waves to curls, curls, curls.
So, from my experience, the way to get the best curl for your hair is to find the right moisture/protein balance for your hair. Just because you aren't aware of damage/dryness doesn't mean the condition of your hair can't be improved. There are products to increase your curl and methods to add curl, but the best natural curl will be brought out by finding the moisture/protein balance and the right products for your hair.
What worked for me won't work for everyone. Some hair doesn't like protein at all, others are picky about the amount of moisture they can/will accept, etc. But, finding the right balance for you, will make all the difference.
Experimenting with too many products to name here. All this great info keeps my head spinning.