Having looked the situation over, here’s what I would have done if I’d been a high-ranking commander in the British Army in charge of the Ypres Salient:
After the first battle, I would have ordered the Old Contemptibles to hold the line. While they held a temporary line, not only would we launch an aggressive recruitment drive over the summer of 1914, but we’d build new roads from just north of Boesinghe to just north of Voormezele with large stone, steel, and concrete defenses and heavy gun batteries to protect it. I would make the line curve inward to a heavily-fortified position, which would mean no one could get very close in their attack without beings queezed into a lethal crossfire in a well-defended reverse salient.
This probably could have been done with immense speed given the talents of the Royal Engineers; I think if they had started immediately after the first battle they could have had it done by the end of 1914.
If England had done this, a smaller force could hold the road to Armentieres while more troops were committed to the Somme to launch an offensive in late 1914, while Falkenhayne’s defenses were still incomplete (by January 1915, they were dug in thoroughly and ready for major action).
The second and third battles of Ypres would have been prevented, thus saving the town from total destruction, and the action would now take place in fields between towns that were easier to hold. The Battle of the Somme, meanwhile, might have been a resounding victory with few losses.
None of these things would have guaranteed a win, but they would have given both sides the chance to avoid heavy losses in violent battles. I think the real tragedy of the Great War was how many people died or lost everything they had, who really didn’t have to. Kitchener wanted a strategy that was guaranteed to win, but by sticking it out in a salient that was barely defensible, it cost more in human lives and resources than it was worth. Better that England had avoided war altogether, but once involved, there were ways to mitigate losses that were not given serious consideration.