I mostly agree with woodcraft, though I still like toe warmers to bridge the gap between "too cold for shoes alone" and "cold enough for full booties".
I have Performance brand booties, but I think any bootie with +/-3 mm neoprene will work fine. I've not seen the need to spend $400+ on winter boots when $40 booties work, but if you're riding a lot then winter cycling shoes might make sense for you. With the booties I like that, if it gets really cold (like single digits °F) I can put a chemical hand warmer packet between the top of my shoe and the bootie and my feet feel fine.
Personally, I don't like to fool with thicker socks, or multiple layers of socks. My shoes fit properly (read tight with little room for thicker socks), so when I've tried thicker socks I've had to significantly loosen the straps, and the fit doesn't seem as good. And, if too thick, then my toes get pinched and colder than if I'd worn thinner socks.. Multiple layers means the risk of bunching and blisters, I'd rather have one sock of appropriate thickness..
I hate the duct tape idea. I mean, sure, in an emergency to keep your toes from freezing, but as a day-to-day solution? No. No, no, no, no.