Im asking on behalf of my drummer friend..

how to choose a good snare ? any particular brand?
and how does the size of the snare effect the sound?
and what type of drumhead?

er that is such a difficult question to answer.
it actually depends on the type of sound that u want.
that will be influenced on the type of music u play and listen to.

sorta like how a guitarist chooses a guitar, there is no hard n fast rule to it.
just have to follow your gut (or your ears! )

it boils down to sound.

drums is interesting because there are so many factors such as:
snare size (depth, diameter), material used, construction, rim material (for rim shots), skin type (so many in the market), and finally (and most importantly) how you tune your snare.

one important note is that a snare would sound different in different rooms. thats why drummers fine tune their snares during soundcheck.

There's no way to answer this question.
If you're looking for a cracky, rock sound, you could get a maple snare drum, with a thicker head and a larger depth and a thicker shell.

If you're looking for a pop snare sound, maybe a 13" snare with a thin head. A metal shell, like a steel or brass shell.

If you prefer ringy snares, go for something thin shelled, and maybe brass or steel. Get a thin head and a smaller size. I've tried a 12x7 hammered brass snare that belonged to my teacher, and it was amazing. It was nice and ringy and had a good pop. but I prefer a more versatile snare.

I have two snares currently, a Dennis Chambers signature snare and a 13" maple piccolo snare. They are very very different and are a great contrast to each other. You should just try out snares at a store and decide.

a high tension FTZ yamaha snare wud be fine. u can hear every inch of strokes u made.

but then again, ur neighbours who lives 2 miles away might not be pleased with it.

i have a shinny silver rare tamburo snare.
my perspective is that it has to be clear (trebleish) especially for modern music and tension is built JUST fine which i feel the tamburo one im selling has