Foot Health for Tennis

Most experienced players know that the health of their feet is a foundational necessity to surviving a grueling tennis competition.  Injuries can take you off the court and cause you to lose matches by having to withdraw if the pain becomes unbearable or if you feel that you are risking permanent injury.  Additionally,  your safety is enhanced if as your movements require more athletic efforts that you have a stable platform to transport yourself around the court.

Shoes

The first thing is to make sure you spend your money on very good tennis shoes.   I've found ASICS to be one of the best though I currently use the Brooks Beast which is as much a running shoe as a tennis shoe.  I ended up finding that shoe by going to a podiatrist to help alleviate back pain.  With a wide platform for a 4EEE width and a high arch this particular shoe is the one recommended to me.  It has served me well for a decade though they aren't inexpensive  but they aren't cheaply made either.  I haven't tried the ASICS in a long time but the reviews suggest they haven't lost their appeal. 
Keep in mind that some running style shoes offer less lateral support than is needed for competitive tennis so find a shoe that provides enough lateral movement protection that you won't easily turn an ankle.  Purely dedicated running shoes tend to sit higher with all the added cushioning and depending on the shape of the shoe might lead to instability on sideways movements.  I learned this the hard way myself but with a very wide shoe it seems less of a problem.

Socks

The second is to consider the quality of the socks you wear and even consider wearing two pairs if you want the extra padding and don't want to go for the high end tennis socks that are out there.  My favorite is shown below.  These are some of the best tennis socks available and the company has been around for decades.  These are thick enough that wearing two pair probably won't suit you but another option is to get an ankle length sport sock and then wear a crew length sock over it.  If they both have moderate or limited padding the combined width will still work.  But if you go for the quality and price for top performance you might try the Thorlos.

Gel Inserts

And finally we get to additional cushioning.  I started using gel inserts because of the time spent on the court just took its toll and this is a good way to soften the feel on the court.    

Final Note:  If you do go with two pairs of socks or even a very thick sport sock and then add gel inserts you may have to go up in size on the shoe.  That is what I have done though it may not be recommended by specialists.  Since I don't play competition any longer and need joint and spine protection this is a good way to soften the shock of hard tennis courts on an old body.  If you are young and spend a lot of time on soft courts then it may not be an issue for you.  

Disclaimer:   
As with all things related to health I recommend that you should consult your health professional and since we're talking feet that would be a podiatrist.  I just shared my experiences that might help you in the decision process.  Use your own judgement and consider the ideas listed above as informational but please do your own research to find the safest and best solution.