ITA with previous posters about length and winter weather results in looser curls. In addition to layers, a protein treatment or using a conditioner with protein may result in a tighter curl pattern or at least it does for me during the winter.
3b/c, medium-coarse, low porosity, low density
HG: Jessicurl Too Shea and Kinky Curly Curling Custard
Shampoo: nonsulfate shampoo and Suave Naturals sulfate shampoo when needed