The most important part is that you try to fix mechanical issues, e.g. the different flexibility of the classes regarding their choice of targets and the connected activity/passivity by tweaking the item balance. Because those things are directly connected to each other. Archer shot speed, accuracy and damage have influence on the fact that archers can choose targets most of the time, infantry can't. Or horse hit points have direct influence on the fact that most infantry players are autowalker-lemming-Rambos who scatter all over the map and then get picked by cavalry. Because cavalry horse HP is too high.
And yet another important aspect is to tweak the popularity of classes by making them (most often) crappier or (almost never) better, which means that the players who play a class because of personal preference and not because of minmaxing have a shitload of fun with it. So if there is too much cavalry or there are too many archers, make the class crappy, so actually no one wants to play it any more except of a few enthusiasts, who will still have their fun with their class, because they are enthusiasts... eventually...
And don't ever come to the idea to reallocate loom points after item balance patches. Otherwise you could see much faster which items people tend to loom and you could see much faster which items are OP. And there would be the danger of actually being fair and not destroying the work of three generations by completely screwing up an item.
