Hoo boy,
that REALLY depends on what you use the car for.
If you road race or autocross, for example, negative camber becomes something you can't have enough of.
If you want ease of parking and a light wheel, caster gets reduced- carefully.
If you want a stable car, you toe it in, but if you want it to turn in quickly, a bit of toe OUT helps a lot.
I do agree with George, tho, that the stock settings are a good starting place. And then get a suspension book, and modify thoughtfully.
I used to think it was a black art, until I got a car that was easy to adjust, and now it's just another tool to adjust my car the way I want it. BUT it's also a way to kill yourself if you don't know what you're doing AND experiment wildly.
fwiw,
t