One of the most rarely stimulated sexual sense is the aural. Yes, I mean the sound of your breath in her ear, the heat of your arousal translated into words. But more than these, I mean sounds generally. At one end of the spectrum, consider putting headphones over her blindfold and playing whatever rousing music you fancy. Think stuff that brings tears to your eyes (as in Mozart's "Requiem", rather than One Direction). Note: while it will increase the stimulation for her to feel at one with the headphones, it makes sense for you also to be playing the same music such that your crescendos coincide.
At the other end, try stopping her ears. Silence is rare, and it's a fair bet she will never have had it imposed on her in a sexual sense. It is incredibly powerful, especially when combined with the blindfold. If she is into it, it is worth getting something customised - the bespoke ones from ProGuard are excellent (from £84.95. proguarduk.co.uk) - to make sure that noise is fully blocked. Have her in a position where she is vulnerable: a dining or massage table, for example. You are free to walk around her and reach to blow across the stiffness of her nipples, or to stroke the wire of her bush. The lightest sensations will make her dizzy.
Perhaps go the whole hog and tie her to the table: this completes the sensation of restraint and has the happy side effect that she won't fall off. But as you work sensation up - running your nails up her inner thigh until she begs, stroking her snatch and then plunging your thumb inside her as you use your four fingers to pull her labia toward your thumb, and then rolling the shaft of her clitoris between your first and second finger - it will be a head rush at new heights.
Original article published in GQ, in April, 2014