I had a hysterectomy 12 years ago and have been suffering from hot flashes on and off all this time. The only advice I can give is as follows:

Soy Products - Soy milk, Tofu, Miso soup, Edamame (watch the added salt). Bonus: Good for your diet!
Black Cohosh - I used to use a product called Remifemin. Worked some but should not be used long term
Find your Triggers - For me it's alcohol. Sometimes a single glass. Be sure to sit in restaurants and bars by the door or window! Another trigger is caffeine, so I limit that to one cup in the morning and green tea later in the day.
Layer your clothing - For years now I have worn a cami top with a shirt on top and in the winter a sweater. It's a-peel-ing!
Slow breathing - when I get a hot flash I close my eyes and do some slow deep breathing to bring my "temperature" down.
Exercise - I read this a lot but only this year have a begun (as you all know) a routine exercise plan. And in hindsight now, they seem to have diminished some, although that just could be part of the process as well.
Fans, Fans, Fans - In my office, portable hand held fans. Worth the investment!
For night - summer cotton pi's - all year long! and a cold pillow! I have even kept my pillow cases in a ziplock in the refrigerator for emergencies!. I read about a pillow on Amazon (Feel Cooler Pillow) but at $80 never bought it (although one of these nights when I can't stand it I am sure a midnight trip to the internet may happen! )

Everyone is different so you will have to find your triggers and remedies. In the meanwhile remember you are not alone!