Create a shoe out of clay. Your shoe should be close to actual size. There are many templates for shoes available. Find one or a few and cut them out of paper. See how everything will fit together. Brain storm ideas for your shoe and get approval before you start working. I want to see a paper version before you start with clay.
day 1 find shoe examples and brainstorm ideas.
Day 2 make a template and start paper mock up.
Day 3 recover template and begin slab work
day 4-5 assemble slabs. Use paper towels to support the slabs. Paper can be left in the shoe. It will burn away.