Ditto on sueinns comments. My PVCs were pretty pervasive, always around. Some of the triggers (lack of sleep, MSG, caffeinated beverages) made them worse, but I never found a natural method for getting rid of them. Some people find that yoga, meditation, or relaxation techniques work for learning to accept the PVCs.
Except for some herbs that a few people have mentioned, I've tried it all with limited success. We need to keep in mind that, in most cases, this is an adrenalin/electrical problem with the heart and not related to mineral deficiencies.
My experience with PVC's is they tend to be chronic and not any one thing will keep them away for long. That being said, there are some triggers.
Alcohol
Caffeine
Stress
Eating a big meal
Lying on your left side or just lying down
Low potassium or magnesium
Hypothyroidism
Perimenopause
Being athletic
So avoiding alcohol, caffeine and stress (yeh, right), eating light meals, taking potassium and/or magnesium supplements, and having your thyroid and hormone levels checked may help.
Some people find drinking really cold water or meditating makes a difference. I find that, for me, taking control and simply ignoring the little suckers works best.