This is how i use my diffuser with the best results:
1. Wash/condition
2. Use LOC method and put my hair in about 10-12 twists
3. Wrap my hair and sleep on it
4. Next morning my hair is still damp and i diffuse it on low so that the curls pop in
For some reason when i diffuse without air drying it i get crunchy curls.
Sometimes i diffuse it to about 70% at night, pineapple it, and the next morning its not so crunchy.