I always do the two sock thing. Seems to work for me. I'm using Ultimax brand liner socks which are a bit thicker than dress socks. I haven't used Smartwool, but I've talked to a lot of people who have used Smartwool and really like it.

I actually carry at least two changes of socks (four pair in other words) of varying weights. Mainly, I carry the extra socks in case I get wet (always have a pair of dry socks in case you have to bivvy), but if I start getting a hot spot, I can try a different sock. Sometimes that's all it takes.

Oh, and duct tape works really well on hot spots. Note, however, that duct tape does not breathe which can be an issue on multi day trips.