Double team her masturbation session
Next time you're masturbating your lover, use her hands as well as your own
Even though it's an amazing sensation for your lover to just lie back and let you masturbate her until orgasm, either with your hands or with a sex toy or both, try getting her involved at the same time and you'll soon double her pleasure.
If you're stimulating her clitoris and vagina, why not get her to stimulate her nipples and breasts? By getting your girl to play around with her other erogenous zones while you set to work on her most intense one, her orgasm will be through the roof!