Type designers always say "trust your eyes", but in fact, once you start working on complex type-design projects (multiple masters, large glyph sets, etc.), you realize this nonsystematic approach has its limits. At the very least, it's time consuming.
That raises the question of how to maintain letter-form consistency when simple copy-paste isn't good enough.
For instance, making the top and bottom halves of an s look "the same" is hard and time consuming. I've recently found myself involving all sorts of measurements in the process. Another example is equalizing the apparent tension (curvature) of rounded shapes which are related but not identical.
How do you approach this issue? Do you freely move nodes around while relying solely on your eyes? And if not, what do you do? If you could describe some key examples in detail, that would be awesome.
On a related note, I'm also interested in what compromises you make in order to keep things simple and manageable. I mean stuff like "all my overshooting letters overshoot by the same amount regardless of their shape", "I skip making letters such as I,l a bit wider", etc.