Monica,
That's pretty cool how you have the American sizes for soles and insoles...I often can't find shoes in my own size right here in the US, never mind soles and insoles!    Will have to take a look and see what's around, but at some point, I may very well be buying from you, which would be wonderful.    I'm not ready to do anything at the moment, but as I mentioned before, I have many ideas for shoes I'd like to someday make and sell. 
Melanie  (cat slave and Official Feline Can Opener) =^.^=

I don't know about your area, i sell them all over the country, mostly personaly, however i have an etsy store, Monymark Handmade 
As I know, all the other sellers have soles by size S, M or L, or mexican size or european size. I sell american size (including half numbers, wide ann Xtra-wide widths).

Monica,
Love these!  <3  What do you use for the shoe bases (soles)?  Are they all flip flop bottoms, or are they something else?
My favorite is that cute ballet shoe with the bow on it.  <3  Is that with a different sole than the others?
The thing that has always deterred me from making shoes is that I never know what to use for the "base" or sole of the shoe.  I have all kinds of ideas for the uppers...but never have figured out the soles. 
Thank you so much for sharing your fantastic work!  <3
Melanie  (cat slave and Official Feline Can Opener) =^.^=

Hello Melanie,
I produce the soles and insoles, for the soles i use a rubber sheet and cut it with the size pattern and i make the insoles with some layered felt+foam fabric or with porkskin.
Actually here many women crochet and the most common sale in my homebussines are the sole sets.
For baby shoes i produce a soft soles with a handmade doble layered felt+foam fabric.
I don't use for regular shoes or boots flip flop bottons because the flip flop sole has different shape and measurement than the regular shoe. However you can embellish the flip flops (check the first and third pictures). 
I'm going to upload some pictures.
 

Monica,
Thank you for posting the pictures of the soles and insoles!  <3  I wonder if any of those materials are available in my area.  I'd love to try making some so I can try interesting shoe designs that can be worn outside, not just as slippers inside the house.  Slippers are okay but nobody really gets to see them!
Thank you for all of that great info!  <3  I can see why you sell so many of the sole sets.    Probably many women don't want to make the soles but love crocheting the uppers! 
Melanie  (cat slave and Official Feline Can Opener) =^.^=