Lets see...
An awl
Good razer type knife
Waxed stitching thread
Stitching Needles (They are blunt tip type)
Something to burnish the edge like antler, burlap, heavy denim ...
Water
Nice to have...
Edger to round the square edges
Slot cutter
Roller Stitch marker/setter
Round punches
I have quite a bit more than this but the list above will get you started. Keep asking questions.