Three kinds of touch all work on the front wall of the vagina, the G-spot area: steady pressure, rubbing over the slightly rougher patch of skin there, and the two together. None of them is the right one.
A good one to try first is the combination: press into the wall and rub it at the same time. With fingers, that is the come-here motion with some pressure behind it. With a toy, it is holding the toy against the wall and making small movements. Then keep whatever feels best to you. Your answer may differ from someone else's, and from one day to the next.
Angle over depth. For most women, short movements aimed at the front wall do more than long, deep strokes. A pillow under your hips when lying on your back, or lowering your shoulders on your hands and knees, turns pressure toward the front wall.
Timing. It usually feels better once you are aroused; see Wet is not the same as ready: how arousal opens the vagina.
Stop if it hurts, burns or feels like a real need to pee (see The urge to pee during sex). If pain lasts, see Toys and your health: when to check with a doctor.