>However, what ruined my experience was that I told them I don't like to use product or heat on my hair because my scalp is sensitive.

I'm right there with you, and not even because of a sensitive scalp.

I'm a guy with long hair, and I follow the advice of Fabio, the man with the best hair of the 20th century: Eat lots of protein, pick a shampoo without a bunch of extra chemicals, use conditioner sparingly, and never blow-dry or use product.