I just use a heavy pair of insulated merino wool socks and that works pretty well for me - and I'm old and have lousy circulation in my feets.
"There is no royal road to this heavy surf-fishing. With all the appliances for comfort experience can suggest, there is a certain amount of hard work to be done and exposure to be bourne as a part of the price of success." From "Striped Bass," Scribner's Magazine, 1881.