Always have what I call a magical ballet spray in your dance bag.

Take a small spritzer bottle, fill it with ¾ rubbing alcohol, ¼ water, and a few drops of whatever essential oil you like.  I like lavender, so that is what I use, but you could also use tea tree oil, lemon, sage, anything.  Spray off your feet after you have finished dancing for the day.  The spray kills odors, gets rid of bacteria, toughens up feet by drying them out and helping to develop calluses and is inexpensive to make. 
Source: Mary Carpenter via Dance Informa

best method to take care of your pointe shoes

To improve the line of your arch and provide better weight distribution, three-quarter or even half-shank your shoes (practice on an old pair first).

Then, stitch one long ribbon in a U-shaped pattern (secure under the drawstring casing on one side, continue under the arch and up the other side).  That helps pull the shoe towards your arch so that it’s more flattering.”
Source: Mary Carpenter for Pointe Magazine

improve arch support in pointe shoes