All footwear must be broken in before any trip, especially leather.
Initially the shoes are to be worn only around the house and for light tasks, then they can be used for progressively heavier tasks until they become molded onto the wearer's foot. A trick is to lace the boots as tight as it is comfortable, wait for an hour and then undo and relace them.
Greasing new leather footwear will make the breaking faster.
When lacing them, also for actual use, the back of the heel must be pushed back firmly.
Proper lacing technique:
Instead of finishing as he did, do a double simple knot as he shows at ankle height and then, while doing the usual shoestring knot, a double loop making sure each coil is side by side and not on top of one another.
Cotton shoelaces are superior and won't come undone easily unlike synthetics.
https://www.youtube.com/watch?v=zEU77jcg4Sg 