I got in the habit many years ago of wearing two pairs of socks for the long days of teaching or for matches. Hard courts are hard on the feet and and joints so any cushioning your can add to your feet will help you in the long run.
The first step is the right shoes. Get a good platform and in particular a wide platform. If you have wide feet then take a look at some shoes that fit the bill.
Next is the insert. As good as shoes might be the addition of get insoles is another add on I've found very useful. I buy a shoe size larger so I can add these along with my two pairs of socks.
gel inserts for shoes
Finally, here at the socks. I use a black interior sock that is low cut so it doesn't reduce circulation on my legs but still gives me the cushioning,