I do TKD, but I suspect everyone's going to be looking for roughly the same things in a MA schoo. Here are some pointers that will probably be useful.
i. Does the school seem well-organized? i.e., does it seem as though the people in charge know what they're doing? This is something that you can often get an immediate feel for, even if you don't have technical knowledge of the art itself.
ii. Does class begin promptly?
iii. Are instructions issued clearly? Does the instructor give at least a general idea of what the particular subject matter that you're about to work on is (forms? individual techniques? balance? impact training? flow exercises? and so on). Are the physical mechanics of the techniques explained at least in broad outline?
iv. Is there a mix of activities? Stretching/breathing-meditation/basic techniques/forms/combat-oriented exercises (these in no particular order, but usually they're sequenced in the order I've listed)?
v. Does the instructional staff watch individual performance carefully and step in to correct or modify students' execution of techniques as needed?
The other questions that arise have to do with your own personal sense of the aesthetics of the art. Do you like arts with a kind of angular, hard approach to combat based on linear strikes? Do you prefer rapid sequences of smoothly flowing strikes? Would your rather work in an MA in which strikes were minimized in favor of controlling moves, locks and throws? Would you like some of each? Etc... for every choice, there's an art which can deliver it, usually more than one. I'd advise you to spend a little bit of exploratory time before making up you mind. Check out as many different schools and arts as you can and see what strikes your fancy!
