Start by wearing the boots at home for short periods with your combat socks and padded chausses. Gradually increase the wearing time as the leather adapts to your feet. Practice walking, crouching, and changing direction, but avoid full-intensity training until the boots feel comfortable.
Use a suitable leather conditioner to keep the material flexible. Do not soak the boots or dry them near an open fire, radiator, or other strong heat source. Stop and check the fit if you notice persistent pressure, numbness, or severe rubbing.