Used to always wear two pairs of socks until I tried some Dahlgren (alpaca/wool) socks on a two week long trip and from then on thats all I wear. Good stuff.

These aren't too bad- a couple hours tied to the outside of my ruck. They are basically a black athletic sock made out of a wool/cotton/poly blend. I just can't stand the feel of the nylon socks- like wearing fish skins. *shudders*

Great post and answers. I am a one sock, LLBean med weight hiking socks, or smartwool, kind of guy. Agree that boot fit and lacing are crucial.

Two socks for me. Synthetic or wool inner, and wool outer. I don't use cotton inners any more; the moisture they hold seems to soften the skin on my feet

I'm not averse to trying the jazzy new single-layer hiking socks, but then I'd have to change my whole fleet of boots.

I have never been a fan of doubling up on socks unless it was for warmth. I spend a lot of time hiking and running in crappy terrain and I found that wearing good socks, good/appropriate shoes and taking care of you feet have worked better for me then using two pair of socks. The operative phase being “worked better for me: and you may find something works better for you. This post will probably go WAY beyond the answer you were looking for… but I can’t sleep…

I have feet that blister easily; I have discovered a few techniques that work very well for keeping my feet blister free and happy. After one of my Ironman where my feet were basically destroyed; my girl friend, mom and a MD friend all bought me the same book; Fixing Your Feet, by John Vonhof which is an excellent resource. In the years since that first Ironman I have also had the opportunity to work at a number of ultra-marathons and have continually perfected my foot care techniques. Besides spending the money on GOOD socks I have found a few keys to keeping your feet happy:

• Tie your shoes. This seems simple, but tie you shoes so that your feet move as little as possible. A simple change in how I laced my shoes (see picture) made a huge difference in foot movement (and thus a reduction in blister reducing friction).
• Keep your feet clean and dry. This is often easier said than done. Here in AZ, I almost always wear lightweight/breathable running gators when out on the train for any period of time to keep the dust and rocks out. Dirty feet are more susceptible to blisters from the increased movement and friction.
• Stay hydrated in hot weather. Seriously, dehydration increases the chance of blisters.
• Use powder or lubricants. Even baby powder from the drug store works, but if you can get a powder designed for blister prevention (like “Blister Shield”) or skin lubricants designed for endurance sports (like “Body Glide”) . I always use Blister Shield for hikes/runs over an hour or so. I personally don’t use a skin lubricant, but I have seen it do wonders for ultra-marathoners.
• Pre-tape your feet. If I know I am going on a hike/run that is going to be rough on my feet, I pre-tape my feet with Kinesio-Tex tape and spray on skin adhesive. Once my feet are taped… I spray the feet completely with the pre-tape skin adhesive and “glue” my socks to my feet. The socks still come on and off really easily and this pretty much guarantees me happy feet.

These methods may be more then you need to do, and simply buying quality socks (Smartwool socks are some of the best) and keeping your feet clean and dry will be enough for most people.

I don't use double socks, however I use my 10-10-20 rule on hikes.

After the first 10 minutes of hiking, stop and adjust my boot laces.

I do the same thing again in 10 minutes then once more in 20 minutes. At this point, my boot laces are perfectly adjusted to my feet and without any slippage from the boots or them being too tight, I can walk all day without getting blisters.

For really tough hiking, like when I am elk hunting, it used to be a pair of synthetic socks beneath a pair of wool boot socks. I never like the feeling of pulling an extra pair of socks over my feet, but I like blisters even less. Then I found Thorlos, and I wear just the one pair now. They have a sock liner that you could use if you felt you really needed to, but since I went to Thorlos, I don't get hot spots, my feet feel drier, and they don't wear out as fast.

Put me down for thin dress socks/heavy wool socks as well. Seems to work well for me. I always carry a spare pair when day hiking just in case.

Another reason to go with a thin synthetic layer covered by wool is that a single pair of wool socks can go quite a while without cleaning by keeping clean layer next to your feet. One pair of wool with three pair of liners will go a long while. Clean the liners you were just wearing each night and don a pair that you washed the previous night. Nylon and CoolMax liners clean and dry easily. $.02

All the backpacking stores tell me one pair is all you need, now
that socks are so well made (smart wool and all). This works fine for me if I am on a trail, and wearing running shoes.

If I am cross country with lots of sidehill neither running shoes
nor one pair of socks cut it. I wear a pair of thin socks OVER my
smart wools, inside of ankle high boots. Better blister prevention
and cushioning from rock bruises.
If I fold down the top of the socks into the boot tops I get
better ankle support.