Help with diffuser?

I’m fairly new to having curly hair (with last couple years) because I never realized I had curly hair. I always knew it had a little wave to it but I would always brush it over to the side.

I discovered I actually do have some pretty nice curls I just had no idea how to take care of it and treat it. I have a fairly good routine now and my curls are fairly decent. I use shea moisture shampoo and conditioner, then I scrunch it with a thin towel, apply some cream (can’t remember the name) and then diffuse it.

However I honestly have no clue how to properly diffuse my hair. Do I just press the diffuser directly against my hair and just bounce around or what’s the best method? I know I’m doing something wrong because some days I get it to look great, other days the curls aren’t as strong looking