[MENTION=82504]Garthanos[/MENTION],
So, another idea for systematizing Martial Practices: One of the problems is the danger of, as I like to put it in the context of adding skills, "creating incompetence." You add a 'create fortified campsite' MP, suddenly everyone else forgets how to fortify campsites. One possible solution is to have (some) MP's require a key skill at a threshold bonus to use, but require no roll. The benefit is not that you're doing something that can't be done with the key skill, but that you do it every time, without any rolls.
For instance, a ninja might have the 'Steal In' martial practice, that requires a stealth check of +20. If you know the practice, have sufficient knowledge of the area you want to infiltrate, use the proper materials, take the requisite time in preparation, and follow the proscriptions of the practice precisely, you become undetectable by normal or supernatural means, until such time as you leave the area, move into an unknown part of it, attempt to interact with creatures or objects within it, or whatever. Basically, push this button, expend these resources, and stuff you could probably do, most of the time, happens automatically, every time.
And, another, 'nuther idea:
Interacting with magic. You could have Martial Practices keying off History (or some other skill you think is appropriate - but probably /not/ the traditional Religion/Arcana/Nature triumvirate of ritual key skills, or at least, not only one of those, but History or Insight or something as an alternative), to represent superstitious/traditional/practical counters to supernatural dangers.
FREX:
Bane Weapon Martial Practice
Make a History check, DC = 15 + level of the creature you are preparing the weapon against. On a success, the weapon takes on a single extra damage type to which the creature is vulnerable, or that exposure to which inhibits one of it's traits or powers. Only the type of creature the weapon has been prepared as a Bane against experiences this extra damage type, in all other ways, the weapon has only its original keywords.
That's actually an old idea I had - for a Rote in M:tA called 'Cryptonite,' - that came to me when I was researching lycanthropy. We all know about the silver bullet, but there were all kinds of superstitious anti-werewolf tricks. Throwing a steel knife over the werewolf's head or tricking it into stepping over a broom, for instance, would force it back into human form. A bullet made from pith(!?) could be deadly to one. (No, really, I'm not making those up.)