Tips on increasing Perineum stimulation?

The perineum and p-spot are two different things, but if you are just referring to the perineum than I find that a warm-up of slow, gentle contractions synced with deep breathing at the beginning of a session really increases it's sensitivity. The wiki describes these warm-ups in detail.

Interestingly, I just got a helix last Friday and it has quickly become my favourite model despite the fact that I feel very little from the p-tab on my perineum.

I just massage my perineum like how I would imagine rubbing a vagina. Feels so good that I can orgasm that way.

Find the triangle where they all meet. I'll strum or rub it while contracting or holding the pressure while moving energies around physically. If I clamp on a spot and contract while massaging then I get this incredible explosion internally. Keep focusing on it and I will ejaculate. Feels very different than a penile orgasm even if they're similar. The sensation is more outward instead of focused at one point. This area just bulges and contracts with a life of it's own.

For me my perineum is probably the third most erogenous external area that just jumps starts my excitement.

Another thing I'll do is just lay in bed with a handheld vibrator and just move it around. Base of the penis, pubic bone, on my glans, shaft, over foreskin on top of glans, perineum, bottom of shaft and testicles, inner thighs, etc.

By itself the vibrator feels good; relaxing. But with an Aneros or plug... It just slowly sinks me down into this fuzzy state of bliss. Combining those two and I can just let go and enjoy the ride.