[AnimalMuppet]

I think it takes being on a project for several years, more than once. You need to see some good ideas turn out to be bad ones, or at least to have some bad side effects. You need to see some features that were developed that turned into maintenance headaches (and some clever hacks that did, too). You need to bump into the issues that the architecture causes, repeatedly.

I think understanding the longer-term consequences of ideas that sound good in the short term is a big part of "good taste".