That's just it. Through the day I make her use a dildo on herself (not her nice iVibe, that she likes too much for this) and fuck herself with it right to the edge of orgasm, then she must stop. Usually with instruction to pinch and twist her nipples, one of which has a bar through it.

When she's done that a few times she is only allowed to finger herself, even less satisfying and therefore more frustrating. But all the time, taking herself to the edge of orgasm but under explicit instruction not to allow herself to cum.