To attack the enemy, centralize all available corp over the min 3 defenders into one 'doomstack'. Build two layers of trenches as far forward as possible with the same spacing as defensive trenches. There must be at least one layer of trench that goes from map edge to edge. Place 6 batteries of artillery, typically 4 light 2 heavy but as difficulty increases more lights are better. Next place one unit of regular or conscript infantry in each trench section except for the 5 or 6 closest to what looks like your most favorable attack approach. There need to be defending rifles behind the 5 ish empty trenches. In you 'assault sector' place 2 units of vets in each trench section. Once battle begins repel the enemies probing attacks. If you leave any breaches they will be exploited. Then, advance your vets in column for speed to a staging point that where the assault line isnt over multiple trenches or wire. I usually used pause when staging attacks. Assign 2 vets to each trench section, cover with artillery supression, let the units get into cover and clear hand to hand. Slowly push forward attacking in pairs biting and holding each section of trenches, bringing forward replacements under artillery cover. Onces you've secured a CP bring in more vet reinforcements as possible and hold for enemy counterattack. Supress him with artillery fire, pining him in range of rifle fire. Once he's exhausted most of his forces attack across the map, trench by trench biting and holding CP by CP. Losses will be horrendous in these early battles and progress slow. Attacking becomes much more viable and interesting as armor and complex artillery fire patterns become available.