Feet are everything, so I'll give you a few tips - from a guy that toured. Shoes ARE important, but many problems are more easily remedied than a shoe-hunt:
NAILS: I make an industrial strength nail sander, with clear, hard, plastic non-skid from Ace Hardware. It's about #40 grit. I use a stick about 1' long (30cm), 1.5" wide (3.5cm), about 1/4" thick (.8cm). I use the sticky back, and cut 4 strips, one for each side and the edges. The sticky doesn't work all that great on porous surfaces, so a strip of plastic on something works. After several 're-paperings', there is enough glue on stick to really help. This 'stick' travels with me to all tournaments, and is in my small, courtside bag (I don't bring those big@ss bags on the court with me). I ALSO KEEP CALLOUSES SANDED DOWN, FEET AND FINGERS. Finger callouses CAN CRACK - and those are really painful for such a tiny little thing. Those soft, foam boards are good for getting thumbs, or I use the edge of the 'board' for that.
KEEP YOUR TOENAILS VERY SHORT. Most player's toenails ARE WAY TOO LONG. I cannot stress this enough. Keep the 'edges' CLEAN and trimmed (hangnails or infections). I hit with a college girl who's feet were a mess. She took off her shoes (lost nails), and I could see the immediate problem; too long. She's never had a toenail issue since that day.
BLISTERS: DO NOT OPEN! Use a sterile pin and poke 3 or 4 holes to drain. LEAVE SKIN ON. Keep those holes open, so air can heal the skin underneath. Wrap with a bandaid that has Triple Antibiotic ointment on it, and change frequently.
BROKEN/STRAINED TOES: All you can do here is tape your toes together. There is no 'cast' for your toe. I had this a lot, at one point, and added some things to my diet from a naturalist dietitian. No more broken toes. Had like 5 - at one time - one summer.
ATHLETE'S FOOT: Although not mentioned above, as I have to use many club/public showers, A/F is a VERY SERIOUS ISSUE.
DO NOT UNDERESTIMATE THIS INFECTION. I did once, and had to have a bone removed from my toe!
I wash my feet WELL, toes, etc., with soap and water.
I use cheapy thongs IN the shower - everywhere.
I bring a small, spray can of Lysol - it kills the bacteria.
I pull liners from used shoes to dry - and put in the sun, with Lysol spray, if I can. SUNLIGHT KILLS BACTERIA.
I use two pairs of shoes per day. One is 'drying' while 2nd is in use. At home, I have 5 or 6 pairs I rotate.
Good luck.