Of course a lot of "soldiering" does not actually apply to the battlefield...

Personal hygine (in awkward circumstances), kit maintenance, scavaging, walking really long distances, etc...

Then there is steadiness underfire, weapon drills (reloading), marksmanship, bayonet drills, marching drills, etc, that make each soldier individually more effective and the formations overall more effective.

Little tricks may not make a difference, but if you veterens can hold fire when instructed, fire accurately when instructed and reload faster (even if it is just a couple of seconds faster) than the men opposite it should make a difference...