Shoot enemy players in the face with a rifle, if you are attacking then do this while advancing.

For NCOs, drop gas on the enemy line to conceal your squad's advance.

Spread out once you are in the enemy trench instead of grouping up and waiting for a mortar/grenade bukkake.

Do this in your own too, pretty much don't group up like a bunch of retarded bees.

If someone is shooting a machine gun at you then get behind cover.

If you are a sniper then shoot at the guy with the machine gun from very far away.

Just shoot everyone as the sniper, use it as a long range spy-check on your teammates.

Congrats, if you managed to read through this whole thing then you are now capable of giting gud at Verdun.