My experience with HRT was short and disastrous. Just three days in, I was sitting at my desk feeling fine, swim bag at my feet because I'd done a good swim that morning.... suddenly I felt really dizzy and strange and the whole right side of my body went numb and weak. A co-worker drove me to the emergency ward, where after a long afternoon and a CAT scan, it was determined that I didn't have a stroke. But I was advised to stop the low-dose Estradiol anyway. Lucky thing I wasn't on it any longer, apparently you have to ease off gradually.
Shortly after I tried a ketagenic diet, as mentioned in the Brain Trust book. That helped a lot; I went from about 16 hot flashes a day to 3 or 4. Unfortunately, I gained a lot of weight from the diet and have yet to succeed in taking it off.
I try to avoid simple carbohydrates as that seems to bring them on. I drink a soy beverage instead of milk (can't digest milk anymore anyway) and eat tofu at least once a week to get the isoflavones.