Best way to learn stalemate lines?

I would like to learn stalemate lines to get better at Diplomacy. 
However,I don't have a good sense about how to go about learning them.
 There seem to be a large number of potential lines and there is no
way I am going to memorize them.

Are there just a few stalemate lines that come up very often that
could be memorized?

Are there basic principles that would allow one to recognize stalemate
lines on the fly?

In e-mail Dip I suppose you could just reference the lines.  In
competitive FtF Dip is it acceptable to reference stalemate lines if
you have them printed up?