My wife enjoys frequent 'blended orgasms'.
Early on she was a clit only gal. One sharp orgasm and she would push me away because she would be too sensitive to be touched.
Once we started with g-spot and later a-spot play - she learned to orgasm from that internal stimulation alone.
Having accomplished that - it was just a matter of putting the two together.
To make this happen she has to be mostly in control - and there are two specific scenarios:
1. After the requisite foreplay - including some oral and a massage. I'll use some combination of dildos, vibrators and fingers to arouse her vaginally. Then when she's ready, she'll grab a vibe (most times the Mystic Wand), lay it on her clit and go for the blended orgasm. It works about 90% of the time.
(Side note: she insists that I massage her groin - the area where her thighs meet the hips on either side of her vulva. There are a ton of blood vessels and nerves that converge there and it does two things; 1st it helps her relax - then because her vulva and crus clitoris are right there, it gets the juices flowing pretty good.
2. After she has had 1 or 2 or 5 orgasms from scenario 1, she'll climb on top (cowgirl) and ride me to 1 or 2 or 5 more! She does this by grinding her a-spot against the head of my penis and grinding her clitoris on my pelvic bone - or sometimes she'll use her Mimi vibe.
We've had lost of time to work out the various nuances - I would say we have it down to a science - but we do have a good system!