The G spot is exists, isn't particularly hidden or hard to find. It's just highly overrated. There is also the P spot and the A spot. Most people also aren't aware there are two points in the backdoor as well. And then of course there is the head of the clitoris. Technically, all of these spots are actually part of the clitoris which is as long as the average male penis.
Those are all stage 1 with the backdoor points being the most critical to achieving sustained high intensity orgasm. For some women, on the right day, you can get there in just a few moments pushing the right button, others will require stages of varied stimulation over a good hour or even two, most will flit somewhere between most of time and hit these extremes sometimes. But in every woman exists the potential for a level of sustained high intensity orgasm that doesn't stop as long as stimulation continues. Get her there and you can do whatever you want for your own pleasure and she won't mind a bit, she'll be too busy contorting and spasming with whole body wracking waves of pleasure.
In that state you can still build orgasmic peaks that for lack of distinctive word she will still call orgasms and you can change it up and do those at various points. No matter how long it took to get there in the first place, triggering an orgasm peak from the clit, vagina, or anally will take only a few seconds. Which is very satisfying for a man. Even hopping in at this point for what would normally be the duration of a lackluster quickie will trigger a multiple highly intense orgasm.
A couple words of warning though. Go about figuring her out wrong and she'll feel like you are treating her like a machine. Also there is a point of sustained orgasm where you've started with the clit head to get things moving and completing an orgasm with that point will bring a finale to things. So when she starts repeating from stimulating her somewhere else don't go back to directly stimulating that place for awhile. Also, she'll need a recovery period afterward. She's going to be a little sore the next day from all those muscle spasms and contractions. And if you do it too much she'll desensitize. If she goes for direct clitoral stimulation with any frequency she probably won't desensitize at all especially using something like a wand massager. There is also a good chance the experience will be so intense she is a little afraid of it.
Stage 2 is most effectively reached through Stage 1. In this state it's much easier, though with repetition, to build lasting associations in the nervous system with other points on the body (especially sensitive ones). It's possible to build these associations to the point where she can orgasm through stroking her hair, kissing her, or light touches. The nipples/breasts are particularly easy since some level of association has usually been formed by contact with them during sex already. Anywhere that is ticklish is an especially good target. It's easy to build associations that are strong enough to trigger/escalate arousal through these things. These associations are both psychological and physical because optimized communication pathways will be formed by the two centers being activated at the same time. Eventually, it's best to work toward caresses all over the surface of the skin.
Stage 3 is when you can stimulate this without actually even touching. Strokes so close she can feel them but not actually making contact. Trust me, if you get to this point. That woman will be yours forever. The sight of you, your smell, the stink of your sweat, and the very idea of your touch will send tremors through her body. Especially the smell of your sweat which makes perfect sense if you've taken the time to pay attention to a woman. There is no limit to how much of a man or how strong the man who shows that much consideration and makes her feel that way is entitled to be.