I don't worry too much about making nice' CSS anymore.
It is too transient to spend too much time on.
The exception would be if i am trying to really squeeze those last kb's away.
If it works, and wont hamper future progress, like with !important usage, then i'm usually fine with it.
In terms of breakpoints, then i usually tell people to stack it until works.
If you need to squeeze something too much, then you are probably not stacking enough.
Optimally i do this stacking without breakpoints, when i need them i usually use
from this list [375, 480, 768. 1024, 1200].
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.