I thought I'd give this thread a little bump as I've repeated this a few times since the time I posted this, first with the partner originally mentioned, and another as well.
The key, it seems, is to apply firm, steady, yet gentle pressure to the mons venus as she's beginning to come, and keeping it there after she may be too sensitive for direct stimulation, either by keeping my hand exactly where it is, or moving on top and holding her tightly, and positioning myself in such a way that my body is applying pressure to that spot. Do that, and it seems like she comes not in one big bang, but big bang followed by rolling, gently dissipating waves.
Sorry for making the above description sound so...clinical...but I wanted to be succinct and accurate in my description.
And, no, I'm not going to make any grand claims that this is a foolproof, 100% infallible instruction kit for mind blowing orgasms every time, but it's worked nicely for me so far
Am I just stumbling onto something that all of the ladies on here already know, or is this an underrepresented technique that more men should pay attention to?