I also love the curly girl method! Have you tried diffusing your hair the pixie method way (see you tube) this adds volume to my hair especially the roots. Also I think the lighter the hair the thinner it can look. My hair is fine/medium but because it's dark it helps it to look thicker. I use oils lightly as I find they weigh my hair down and can make it look stringy. I use Curls Milkshake, this is a lightweight leave in conditioner.
My hair has thickend up since I have stopped using heat, less breakage I suppose..
My goal is to embrace the curls I've been fighting all my life..