I've always found the best technique to get dogs living in the same household together to stop fighting is simply to walk them together.

"A walk, who'd have thought?" - Cesar Millan (The Dog Whisperer)

It actually is true. My dogs Tatum and Shawnee fought a couple times and trust me, they were friggin' relentless when they fought each other, then I started walking them together every day (rather than walking each of my 3 dogs individually), in fact, often I walk all 3 at once now, and it is proving to be extremely effective at forming the pack mentality and thus preventing brawls within the pack.