Vibrators
Use various vibratory toys externally. A broad vibrator (like a wand) can stimulate a wide area (vulva, perineum, shaft of penis) all at once, while a precision vibrator (like a bullet) can be used on a focused spot (clitoral glans, nipples, frenulum of penis). Try using through fabric (press vibrator over underwear) for a diffused feel, and explore patterns or pulsing settings as a kind of “vibrational language.”