finding a big stone somewhere in the woods forming the stone with another stone hit the stone on the other if possible, find a stone that's already close to the shape you want to save the trouble fine shaping and rounding off
vintage woodworking tools australia, sharpening with another, denser stone grinding down to shape; the water softens and keeps the axe head from chipping or cracking more sharpening and then some polishing with water and a cloth polished axe head, ready to go!
making a stone chisel cutting a tree down for the handle bringing the tree down to size making a mortise in the wood for the head to go in opening up the mortise softening the wood with a coal for further shaping; this also treats the wood and prevents splitting carving the handle with our chisel shaping the wood with a hot coal from the fire with how the handle was built, the axe will get tighter with each swing rather than looser...
...but make your mortise big enough to not touch the sides of your stone. that increases chances of splitting. finished celt!