Tips on how to use the Revlon for thick curly hair?

I hear so many good things about this, and I’ve watched so many tutorials, but I feel like nothing I do results in the sleek roots I see on ppl who use this. I do the right prep, I go under and over with at least 3 passes, I try to have tension, I wait until it’s semi dry but not totally … I follow all the rules but I always end up with frizzy roots and it’s driving me crazy :’) any tips & tricks appreciated ! I really wanna perfect my at home blowout but I can’t afford anything more luxurious than the Revlon atm