The fabric closest to your feet has the most impact on them.
Don’t imagine the old cotton athletic socks in your drawer will do. They don’t. They aren’t designed for walking long distances, they’re designed for chasing inflatable rolling orbs around a sporting green. For hikers, cotton socks are blisters waiting to happen. Avoid them. Also: cotton loses its insulating power when wet.
Shell out the extra money and invest in hiking socks made of synthetic wicking fibers that move moisture away from your feet (imperfectly, but far better than cotton). Some people wear wool socks with thin synthetic liners. All these liners do is protect your feet from harsh wool and add weight. If you go synthetic, you don’t need the liners.
Also, synthetics do a better job of insulating when they’re wet.
Some hiking socks have extra padding in them — I find it doesn’t add that much comfort and just tends to make your feet hotter. Your mileage will vary.
Whatever you do, don’t scrimp on socks.