"Ugh. That's going to be hard to change, no matter how we do it," Rita gripes, then notices the plate of cookies he brought over. "Give me one of those." She grabs one, munches on it, and ponders some more.

"Okay, try it like this..."

For the next while, she'll try coaching him with advice that comes in varying degrees of vague until it seems like they've touched on some way to use his sign's altered effects. It'll likely take considerable time and practice for him to bring those effects out deliberately and consistently, however.