Forgive me if I'm not using the correct terminology, but the under-layer of my hair (is there a name for that?) shrinks more than the layer on top, so it makes the bottom few inches of my hair look really thin.

I don't know if it's a different curl type or just that the hair on top has lost some curl from sun exposure, etc.

I think they're both pretty, but since I want my hair to look longer, I would like to maximize the length of the under-layer so it matches. My stylist suggested putting metal clips on the bottom of the curls I want to stretch as they dry, but that's a lot of curls!

Currently, I put KCKT onto my wet hair, comb it through, scrunch out excess water with a flour-sack towel and sit under a hard-bonnet dryer until it's nearly dry. When I have the patience, I clip at my part before drying.

Suggestions? I'd appreciate any advice!
*3B, medium/fine, normal porosity, normal elasticity, shoulder-length when dry.