I've won 4 NTs over all my IDs, and made the S16 around 20 times.
In my opinion, after you get to the elite 8 (or maybe even the S16), all the teams are good enough that the RNG outweighs anything you can do gameplanning.
In terms of getting to that point, it's almost all recruiting, although I agree with cornfused that experience (IQ) is a big factor.
So, my best advice is to recruit a great class or two, and then wait until they are seniors.