First I drew a line about 0.8-10mm inwards and parallel to the rim of the outer sole to determine the outer line of nails. I marked the spacing with the awl, varying width according to expected strain and abrasion. To judge this I simply looked at my first pair of caligae, which I made over 10 years ago and which I know to have more than 400km on them.



Follwing the markings I first did the outer line of nails.

After completing the outer row, I marked and nailed the inner design. I chose the same design as on my old caligae again (as you know there's all kinds of designs, from straight lines to pictorial stuff like tridents, swastikas and such, some occuring all the time, others specific to certain periods).



This is what the insole looks like after nailing...



makes you understand what the originals look like after a few centuries (this one from Mainz)

Time needed for cutting insole, glueing it in, preparing nailing design, and nailing (one shoe): 2h 30min