Stem Direction

Where do you draw the line?

I find myself favoring the second space on the staff. A and below is up and B and above is down.

But then I get to eighth notes where one is below and one is above and have a conniption about it. I end up basing those on which is farther from my line.

Simple, anything above the B line will be drawn stem down. Anything below stem up. Once you get to ledger lines on the top part of the staff you will always draw stems to the down to the B line.

Stems usually go an octave. So if you have a stem that starts on d4, you will draw it unitl you get to d5. Pretty simple.