Never draw fire - it irritates everyone around you. No combat ready unit ever passed inspection. No inspection ready unit ever passed combat. Make it too tough for the enemy to get in, and you can't get out. Both sides are convinced they're about to lose, they're both right.
Professionals are predictable, but the world is full of dangerous amateurs.
Fortify your front and you'll get your rear shot up. When in doubt, empty your magazine. In war, important things are very simple and all simple things are hard. Don't look conspicuous, it draws fire. Communications will fail as soon as you need fire support desperately.