I'm not the most prolific warmonger, though I did manage 19th place in this war, so I like to think I'm qualified for answering this question.
The key to warring is efficiency. This leads to spending gold on stuff like the Ambush Potion, as xDeathlordx mentioned, for an initiative bonus and turning off Ready Inventory before Battles to save time. This isn't a general strategy since switching items before battles is usually very important, especially against bosses. Simply put, warring involves unconventional strategies for greater efficiency.
There are two trains of thought with regards to efficiency: efficiency in turns taken and efficiency in resources used.
The former involves dealing as much damage as possible to prevent monsters taking a turn since the latter animations can take up precious time. This involves QC skills like Buffalot's Beach Bod/Arcane Amplification and nukes. The issue is that this takes setup time and requires spam-clicking Essence Orb to replenish resources. This is the route I take in warring.
The latter involves dealing as much damage as possible while using as few resources as possible. This is the idea behind xDeathlordx's strategy. Since elelocked armors get massive elecomp on their normal attacks, their normal attacks do a lot more damage, almost up to armor skill levels of damage. This is a normal attack, so SP and MP aren't required. There is no need for spam-clicking. The issue is that without setup or nukes, this is obviously weaker than the former strategy. Stronger monsters will absolutely take their own turns, which can take up time.
Regardless, both strategies aim to reduce the time needed to kill monsters as much as possible since the real limiting factor in warring is time. With sufficient time, one can massively extend one's caps far beyond what is expected. That is, in fact, how many of the top ten placers got so many kills. They set a really low gold limit and fled from all monsters that give more gold than that. This does make generating momentum impossible, so BtH and damage will be lower than for normal players. This means they take even more time for battles than normal beside just finding monsters to fight. Time is the limiting factor.
As to how my personal setup changes between warring and normal questing: I take out my armor imbues and Purple Rain since those take up time. Normal optimal play for me involves using imbues and Purple Rain to maximize damage and resource efficiency, but that takes time that I need during wars. Otherwise, my build doesn't really change since I nuke in normal play as well.