A couple fo weeks or so ago, I bought some white jazz boots off ebay as they were of a similar style to Regency and Victorian boots (2 periods I plan to do/start on next year). It worked out cheaper to buy white boots and dye them black so that is what I did. Before I did that I had bought some 5mm thick leather (I expect something slightly thinner will also do, but this was the only thickness I could get hold of) and drew around the boot to get a shape for the sole and cut it out with a stanley knife. The heel part needed to be cut off as these are separate on the jazz boots.
Once the boots had had 2 coats of dye (Dylon Shoe and Accessories dye) I started to attach the leather soles. Luckily I had some thin black leather at home which I used for the sides of the heel. I then stuck on the thick leather soles - the main sole was quite hard to do as this required pegs and carrier bags to tie the boot and sole together so they stick! To glue the soles on I used, what has been recommended, Shoe Goo and it certainly does do the job well. I also put some Shoe Goo on the edges of the leather to protect them when wearing outside.
When this was done, I made up a couple of organza ribbon rosettes - 1/2" wide and a metre long makes 2 reasonably sized ones. I the ribbon in half and neatened both ends before running gathering stiches along one edge. I pulled the gathers as far as they would go and then arrange and stitched it into a rosette shape. I glued the rosettes onto the toe of the boots with a blob of Shoe Goo.