Socks aren't a big deal to me. 9/10 I wear whatever basic socks are currently in rotation from Walmart (so Peds or Avia, most likely). That 1/10 is when I have on my compression socks from/for my flight.
As far as avoiding foot pain, I have a pretty solid routine that seems to work well for me. Of course, this isn't meant as medical advice. Please consult your personal medical provider!
Most importantly, change shoes/socks mid-day. I tend to go from my Asics to my Sketcher sandals or vice versa depending on the day. On my trip last week, one day (*one!*) I didn't change mid-day, and my feet were substantially more cranky by the end of the day! I try to remember to take some ibuprofen at this time too, assuming I've had lunch, or am on my way to do so.
When getting back to my motel, I take another full dose of ibuprofen for it's anti-inflammatory properties. I then start the shower, and sit on the edge of the tub while I soak my tootsies in hot water for 10-15 minutes. Afterwards, I will rub mint lotion or body butter into my feet. They "hate" it and are super-sensitive at that point, but it helps me relax. Bath and Body Works has a wonderful eucalyptus and spearmint body butter that's lovely! Even my hubs doesn't mind using it.
When I follow my routine, I usually wake up without any soreness. This last trip, we had my 7yo grandson with us, and I didn't do my nightly foot/leg soaks, and could tell the difference each morning :-(