In 2010, Lee Holeva, a Roman legion reenactor, lavishly documented his efforts to create a faithful reproduction of caligae, the "ancient milspec Roman footwear" (as Bruce Sterling calls it), worn by Roman legionary soldiers and auxiliaries throughout the Roman Republic and Empire.
The same site has further instruction for would-be legionnaires, including calcae, lorica segmantata, balteus, and more.
Holeva's commentary on the quality of different hobnails and hard-won knowledge about various glues are fascinating reading, but the caligae themselves take center stage. As Sterling writes,
*Just look at the industrial intricacy of that Roman Imperial design. What a weird mix of delicacy and martial ruthlessness. Those caligula guys weren't kidding around. All roads lead to Rome and this is precisely how you march those roads.
Making Authentic Caligae
[Lee Holeva/Legio Tricesima Ulpia
Victrix, Cohors Tertia]
(via Beyond the Beyond)